diff --git a/.circleci/config.yml b/.circleci/config.yml
index cc29bcf..589406d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,87 +1,38 @@
-version: 2.0
+version: 2.1
 
-jobs:
-  ruby2.2:
-    docker:
-      - image: circleci/ruby:2.2
-    steps:
-      - checkout
-      - restore_cache:
-          key: gemfile-2-2-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-      - run: bundle install -j3 --path vendor/bundle
-      - save_cache:
-          key: gemfile-2-2-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-          paths:
-            - vendor/bundle
-      - run: bundle check --path vendor/bundle
-      - run: bundle exec rubocop
-      - run: |
-          bundle exec rspec --profile 10 \
-                            --format RspecJunitFormatter \
-                            --out tmp/results/rspec.xml \
-                            --format progress \
-                            $(circleci tests glob "spec/**/*_spec.rb" | circleci tests split --split-by=timings)
-      - store_test_results:
-          path: tmp/results
+docker-auth: &docker-auth
+  auth:
+    username: $DOCKERHUB_USERNAME
+    password: $DOCKERHUB_ACCESS_TOKEN
 
-  ruby2.3:
-    docker:
-      - image: circleci/ruby:2.3
-    steps:
-      - checkout
-      - restore_cache:
-          key: gemfile-2-3-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-      - run: bundle install -j3 --path vendor/bundle
-      - save_cache:
-          key: gemfile-2-3-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-          paths:
-            - vendor/bundle
-      - run: bundle check --path vendor/bundle
-      - run: bundle exec rubocop
-      - run: |
-          bundle exec rspec --profile 10 \
-                            --format RspecJunitFormatter \
-                            --out tmp/results/rspec.xml \
-                            --format progress \
-                            $(circleci tests glob "spec/**/*_spec.rb" | circleci tests split --split-by=timings)
-      - store_test_results:
-          path: tmp/results
-
-  ruby2.4:
+jobs:
+  bundle:
+    parameters:
+      ruby_version: { type: string }
     docker:
-      - image: circleci/ruby:2.4
+      - image: cimg/ruby:<< parameters.ruby_version >>
+        <<: *docker-auth
     steps:
       - checkout
       - restore_cache:
-          key: gemfile-2-4-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-      - run: bundle install -j3 --path vendor/bundle
+          key: gemfile-<< parameters.ruby_version >>-{{ checksum "Gemfile" }}
+      - run: bundle install -j3
       - save_cache:
-          key: gemfile-2-4-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
+          key: gemfile-<< parameters.ruby_version >>-{{ checksum "Gemfile" }}
           paths:
             - vendor/bundle
-      - run: bundle check --path vendor/bundle
-      - run: bundle exec rubocop
-      - run: |
-          bundle exec rspec --profile 10 \
-                            --format RspecJunitFormatter \
-                            --out tmp/results/rspec.xml \
-                            --format progress \
-                            $(circleci tests glob "spec/**/*_spec.rb" | circleci tests split --split-by=timings)
-      - store_test_results:
-          path: tmp/results
 
-  ruby2.5:
+  ruby:
+    parameters:
+      ruby_version: { type: string }
     docker:
-      - image: circleci/ruby:2.5
+      - image: cimg/ruby:<< parameters.ruby_version >>
+        <<: *docker-auth
     steps:
       - checkout
       - restore_cache:
-          key: gemfile-2-5-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-      - run: bundle install -j3 --path vendor/bundle
-      - save_cache:
-          key: gemfile-2-5-{{ checksum "Gemfile" }}-{{ checksum "selligent.gemspec" }}
-          paths:
-            - vendor/bundle
+          key: gemfile-<< parameters.ruby_version >>-{{ checksum "Gemfile" }}
+      - run: gem install bundler:2.3.26
       - run: bundle check --path vendor/bundle
       - run: bundle exec rubocop
       - run: |
@@ -93,12 +44,19 @@ jobs:
       - store_test_results:
           path: tmp/results
 
-
 workflows:
   version: 2
   build:
     jobs:
-      - ruby2.2
-      - ruby2.3
-      - ruby2.4
-      - ruby2.5
+      - bundle:
+          context: org-global
+          matrix:
+            parameters:
+              ruby_version: ['2.7', '3.0']
+      - ruby:
+          context: org-global
+          matrix:
+            parameters:
+              ruby_version: ['2.7', '3.0']
+          requires:
+            - bundle
diff --git a/.rubocop.yml b/.rubocop.yml
index 0414e19..a7e2b20 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,3 +1,6 @@
+AllCops:
+  TargetRubyVersion: 2.7
+
 Metrics/BlockLength:
   Exclude:
     - 'spec/**/*'
diff --git a/Gemfile b/Gemfile
index 6c1e57e..8d62d5b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 group :development do
diff --git a/lib/selligent/middlewares/authorization.rb b/lib/selligent/middlewares/authorization.rb
index 2499d57..a0f0a0d 100644
--- a/lib/selligent/middlewares/authorization.rb
+++ b/lib/selligent/middlewares/authorization.rb
@@ -8,7 +8,7 @@ module Selligent
   module Middlewares
     # Auth is a Faraday middleware
     class Authorization < ::Faraday::Middleware
-      AUTH_HEADER = 'X-ApiKey'.freeze
+      AUTH_HEADER = 'X-ApiKey'
 
       def call(env)
         env[:request_headers][AUTH_HEADER] = auth_header
diff --git a/lib/selligent/version.rb b/lib/selligent/version.rb
index cc33de8..11d81f3 100644
--- a/lib/selligent/version.rb
+++ b/lib/selligent/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Selligent
-  VERSION = '0.1.3'.freeze
+  VERSION = '0.1.3'
 end
diff --git a/selligent.gemspec b/selligent.gemspec
index 0abdfbc..415b4b3 100644
--- a/selligent.gemspec
+++ b/selligent.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 lib = File.expand_path('lib', __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'selligent/version'
@@ -12,14 +14,15 @@ Gem::Specification.new do |s|
   s.summary     = 'Selligent Ruby API client'
   s.description = 'Provides access to the Selligent REST API'
   s.license     = 'MIT'
+  s.required_ruby_version = '>= 2.7'
 
-  s.files       = `git ls-files -z`.split("\x0").reject do |f|
+  s.files = `git ls-files -z`.split("\x0").reject do |f|
     f.match(%r{^(test|spec|features)/})
   end
 
   s.require_paths = ['lib']
 
-  s.add_development_dependency 'bundler', '~> 1.16'
+  s.add_development_dependency 'bundler', '~> 2.3'
   s.add_dependency 'faraday'
   s.add_dependency 'faraday_middleware'
 end
diff --git a/spec/selligent/client/content_spec.rb b/spec/selligent/client/content_spec.rb
index 740ae95..9327333 100644
--- a/spec/selligent/client/content_spec.rb
+++ b/spec/selligent/client/content_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Content do
diff --git a/spec/selligent/client/cumulio_spec.rb b/spec/selligent/client/cumulio_spec.rb
index a4b5e73..2e992ae 100644
--- a/spec/selligent/client/cumulio_spec.rb
+++ b/spec/selligent/client/cumulio_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Cumulio do
diff --git a/spec/selligent/client/data_spec.rb b/spec/selligent/client/data_spec.rb
index 6ad8a71..013e6b8 100644
--- a/spec/selligent/client/data_spec.rb
+++ b/spec/selligent/client/data_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Data do
diff --git a/spec/selligent/client/journeys_spec.rb b/spec/selligent/client/journeys_spec.rb
index 59cd66c..cb7f1fd 100644
--- a/spec/selligent/client/journeys_spec.rb
+++ b/spec/selligent/client/journeys_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Status do
diff --git a/spec/selligent/client/lists_spec.rb b/spec/selligent/client/lists_spec.rb
index 4d40a1c..f360d04 100644
--- a/spec/selligent/client/lists_spec.rb
+++ b/spec/selligent/client/lists_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Lists do
diff --git a/spec/selligent/client/organizations_spec.rb b/spec/selligent/client/organizations_spec.rb
index b40f03e..5b44022 100644
--- a/spec/selligent/client/organizations_spec.rb
+++ b/spec/selligent/client/organizations_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Organizations do
diff --git a/spec/selligent/client/single_batch_spec.rb b/spec/selligent/client/single_batch_spec.rb
index b4b63e8..a53d6c7 100644
--- a/spec/selligent/client/single_batch_spec.rb
+++ b/spec/selligent/client/single_batch_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::SingleBatch do
diff --git a/spec/selligent/client/status_spec.rb b/spec/selligent/client/status_spec.rb
index 6e2038e..c9f332d 100644
--- a/spec/selligent/client/status_spec.rb
+++ b/spec/selligent/client/status_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Journeys do
diff --git a/spec/selligent/client/stored_procedures_spec.rb b/spec/selligent/client/stored_procedures_spec.rb
index cbab010..6e9ddda 100644
--- a/spec/selligent/client/stored_procedures_spec.rb
+++ b/spec/selligent/client/stored_procedures_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::StoredProcedures do
diff --git a/spec/selligent/client/tasks_spec.rb b/spec/selligent/client/tasks_spec.rb
index 7473c8c..6984ef9 100644
--- a/spec/selligent/client/tasks_spec.rb
+++ b/spec/selligent/client/tasks_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Tasks do
diff --git a/spec/selligent/client/transactional_bulk_spec.rb b/spec/selligent/client/transactional_bulk_spec.rb
index 82826b7..02cdb0b 100644
--- a/spec/selligent/client/transactional_bulk_spec.rb
+++ b/spec/selligent/client/transactional_bulk_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::TransactionalBulk do
diff --git a/spec/selligent/client/transactionals_spec.rb b/spec/selligent/client/transactionals_spec.rb
index 81afb23..dcb8a86 100644
--- a/spec/selligent/client/transactionals_spec.rb
+++ b/spec/selligent/client/transactionals_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client::Transactionals do
diff --git a/spec/selligent/client_spec.rb b/spec/selligent/client_spec.rb
index d3b2b81..e4580bf 100644
--- a/spec/selligent/client_spec.rb
+++ b/spec/selligent/client_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Client do
diff --git a/spec/selligent/configuration_spec.rb b/spec/selligent/configuration_spec.rb
index c4953a8..b3e6592 100644
--- a/spec/selligent/configuration_spec.rb
+++ b/spec/selligent/configuration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 RSpec.describe Selligent::Configuration do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 6400d62..7ddc12a 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'selligent'
 require 'timecop'
 require 'webmock/rspec'