Add New Comment on your post notifications

This notification is sent only to the post owner, unless this person turned off the notifications.
A simple first step into the notifications by mail world :)

The mail contains a link to user profile
The link to the user profile is required to give an easy access to
notifications disabling.

Also having a preview for the notify_post_owner method

We can `Comment.first` because it is part of the db:seeds method. So
there should, in development, always be one.

config/environments/test.rb

@@ -9,7 +9,6 @@ ENV["POSTS_PER_PAGE"] = "15"
 
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
-  
   # For Devise
   config.action_mailer.default_url_options = { host: 'localhost:3000' }
 
@@ -46,6 +45,7 @@ Rails.application.configure do
   # The :test delivery method accumulates sent emails in the
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
+  config.active_job.queue_adapter = :test
 
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr