enable sucker punch for heroku (#878)

Gemfile

@@ -9,6 +9,7 @@ gem 'aws-sdk'
 gem 'best_in_place'
 gem 'delayed_job'
 gem 'delayed_job_active_record'
+gem 'sucker_punch'
 gem 'devise'
 gem 'doorkeeper'
 gem 'dotenv-rails'

Gemfile.lock

@@ -244,6 +244,8 @@ GEM
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
+    sucker_punch (2.0.2)
+      concurrent-ruby (~> 1.0.0)
     thor (0.19.1)
     thread_safe (0.3.5)
     tilt (2.0.5)
@@ -299,6 +301,7 @@ DEPENDENCIES
   simplecov
   slack-notifier
   snorlax
+  sucker_punch
   tunemygc
   uglifier
 
@@ -306,4 +309,4 @@ RUBY VERSION
    ruby 2.3.0p0
 
 BUNDLED WITH
-   1.13.3
+   1.13.6

config/application.rb

@@ -9,6 +9,10 @@ Bundler.require(*Rails.groups)
 module Metamaps
   class Application < Rails::Application
     config.active_job.queue_adapter = :delayed_job
+    if ENV['ACTIVE_JOB_FRAMEWORK'] == 'sucker_punch'
+      config.active_job.queue_adapter = :sucker_punch
+    end
+
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.