Publish CloudWatch metrics for processed and failed jobs

This should allow us to display these values on the dashbaord (#5).

lib/funktor.rb

@@ -1,6 +1,7 @@
 require "funktor/version"
 require 'funktor/aws/sqs/event'
 require 'funktor/aws/sqs/record'
+require 'funktor/counter'
 require 'funktor/job'
 require 'funktor/worker'
 require 'funktor/middleware_chain'

lib/funktor/active_job_handler.rb

@@ -3,6 +3,11 @@
 module Funktor
   class ActiveJobHandler
 
+    def initialize
+      @failed_counter = Funktor::Counter.new('failed')
+      @processed_counter = Funktor::Counter.new('processed')
+    end
+
     def call(event:, context:)
       event = Funktor::Aws::Sqs::Event.new(event)
       puts "event.jobs.count = #{event.jobs.count}"
@@ -20,10 +25,12 @@ def dispatch(job)
         Funktor.active_job_handler_middleware.invoke(job) do
           job.execute
         end
+        @processed_counter.incr(job)
       # rescue Funktor::Job::InvalidJsonError # TODO Make this work
       rescue Exception => e
         puts "Error during processing: #{$!}"
         puts "Backtrace:\n\t#{e.backtrace.join("\n\t")}"
+        @failed_counter.incr(job)
         attempt_retry_or_bail(job)
       end
     end

lib/funktor/counter.rb

@@ -0,0 +1,42 @@
+module Funktor
+  class Counter
+    attr_accessor :dimension
+
+    def initialize(dimension)
+      @dimension = dimension
+    end
+
+    def incr(job)
+      put_metric_to_stdout(job)
+    end
+
+    def put_metric_to_stdout(job)
+      puts Funktor.dump_json(metric_hash(job))
+    end
+
+    def metric_hash(job)
+      {
+        "_aws": {
+          "Timestamp": Time.now.strftime('%s%3N').to_i,
+          "CloudWatchMetrics": [
+            {
+              "Namespace": ENV['FUNKTOR_APP_NAME'],
+              "Dimensions": [["WorkerClassName"]],
+              "Metrics": [ # CPU, Memory, Duration, etc...
+                           {
+                             "Name": dimension,
+                             "Unit": "Count"
+                           }
+              ]
+            }
+          ]
+        },
+        "WorkerClassName": job.worker_class_name,
+        "#{dimension}": 1
+        #"count": value,
+        #"requestId": "989ffbf8-9ace-4817-a57c-e4dd734019ee"
+      }
+      #data[key] = value
+    end
+  end
+end