add redis cache and heroku config

Gemfile

@@ -21,6 +21,8 @@ gem 'webpacker', '~> 5.0'
 gem 'turbolinks', '~> 5'
 # Use Redis adapter to run Action Cable in production
 gem 'redis', '~> 4.2.5'
+# Ruby wrapper for hiredis (protocol serialization/deserialization and blocking I/O)
+gem 'hiredis', '~> 0.6.3'
 # Use Active Model has_secure_password
 gem 'bcrypt', '~> 3.1.7'
 # Flexible authentication solution for Rails with Warden

Gemfile.lock

@@ -129,6 +129,7 @@ GEM
     globalid (0.4.2)
       activesupport (>= 4.2.0)
     hashie (4.1.0)
+    hiredis (0.6.3)
     i18n (1.8.10)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.4)
@@ -389,6 +390,7 @@ DEPENDENCIES
   database_cleaner
   devise (~> 4.7.3)
   dotenv-rails
+  hiredis (~> 0.6.3)
   listen (~> 3.3)
   lograge (~> 0.11.2)
   mobility (~> 1.1.1)

Procfile

@@ -0,0 +1,2 @@
+web: bundle exec rails server -p $PORT
+worker: bundle exec sidekiq -t 25

config/environments/production.rb

@@ -56,7 +56,7 @@ Rails.application.configure do
   config.log_tags = [ :request_id ]
 
   # Use a different cache store in production.
-  # config.cache_store = :mem_cache_store
+  config.cache_store = :redis_cache_store, { url: ENV['REDIS_URL'] }
 
   # Use a real queuing backend for Active Job (and separate queues per environment).
   # config.active_job.queue_adapter     = :resque