remove activejob configuration and base class

Except for specific and relatively uncommon circumstances,
Sidekiq has a perfectly sufficient API and commonly used
conventions, and doesn't need an abstraction/wrapper around it.

Author: hiattp

app/jobs/application_job.rb

@@ -19,9 +19,6 @@ class Application < Rails::Application
     # -- all .rb files in that directory are automatically loaded after loading
     # the framework and any gems in your application.
 
-    # Use Sidekiq as ActiveJob backend
-    config.active_job.queue_adapter = :sidekiq
-
     # Configure generators, see: http://guides.rubyonrails.org/generators.html
     config.generators do |g|
       # Create appropriate tests in spec/ not test/

config/application.rb

@@ -5,7 +5,7 @@
 #
 # Client Size = Puma Workers * (Puma Threads / 2) * Heroku Web Dynos
 #
-# Server Size = (Redis Connection Limit - Client Size - 2) / Heroku Job Dynos
+# Server Size = (Redis Connection Limit - Client Size - 2) / Heroku Worker Dynos
 # Server Size is set in sidekiq.yml in concurrency setting.
 # Server size is concurrency + 2.