Bump guard from 2.15.0 to 2.17.0

Gemfile

@@ -8,7 +8,7 @@ gemspec
 group :development do
   gem 'coveralls', require: false
   gem 'fakeweb', '~> 1.3.0'
-  gem 'guard', '~> 2.15.0'
+  gem 'guard', '~> 2.17.0'
   gem 'guard-rspec', '~> 4.7.3'
   gem 'listen', '~> 3.1.5'
   gem 'rspec', '~> 3.8.0'

Gemfile.lock

@@ -9,7 +9,7 @@ GEM
   specs:
     ast (2.4.0)
     byebug (11.0.0)
-    coderay (1.1.2)
+    coderay (1.1.3)
     coveralls (0.8.22)
       json (>= 1.8, < 3)
       simplecov (~> 0.16.1)
@@ -19,9 +19,9 @@ GEM
     diff-lcs (1.3)
     docile (1.3.1)
     fakeweb (1.3.0)
-    ffi (1.9.25)
+    ffi (1.15.1)
     formatador (0.2.5)
-    guard (2.15.0)
+    guard (2.17.0)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
       lumberjack (>= 1.0.12, < 2.0)
@@ -42,10 +42,10 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
-    lumberjack (1.0.13)
+    lumberjack (1.2.8)
     method_source (0.9.2)
     nenv (0.3.0)
-    notiffany (0.1.1)
+    notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
     parallel (1.14.0)
@@ -61,9 +61,9 @@ GEM
     psych (3.1.0)
     rainbow (3.0.0)
     rake (12.3.2)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rb-fsevent (0.11.0)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
     rspec (3.8.0)
       rspec-core (~> 3.8.0)
       rspec-expectations (~> 3.8.0)
@@ -107,7 +107,7 @@ DEPENDENCIES
   bundler (~> 1.16.2)
   coveralls
   fakeweb (~> 1.3.0)
-  guard (~> 2.15.0)
+  guard (~> 2.17.0)
   guard-rspec (~> 4.7.3)
   listen (~> 3.1.5)
   mailinator!