Description:

Create a database credentials yml file that holds the path to the username and password files.
Create an initializer that adds the credentials to ActiveRecord.

Example:

rails generate db_credentials database_name

This will create:
  If they dont exist:
    config/initializers/database_credentials.rb
    config/database_credentials.yml

Otherwise for: 
  config/database_credentials.yml
    It will insert the entry for the named database, if one doesnt already exist.