Rename 'testing' curriculum to 'testing-rails-applications'

Fixes railsbridge#613

Author: tjgrathwell

sites/en/docs/docs.step

@@ -24,7 +24,7 @@ site_desc 'message-board', <<-MARKDOWN
 Build a message board! This curriculum is for students who have completed the Suggestotron and the Job Board curricula. This curriculum is a challenge because it won't tell you what to type in!
 MARKDOWN
 
-site_desc 'testing', <<-MARKDOWN
+site_desc 'testing-rails-applications', <<-MARKDOWN
 Increase the stability of your Rails app by learning about tests: what they are, why they're used, and how to use them! This curriculum is for students who have completed the Suggestotron, the Job Board, and the Message Board curricula. There will be challenges!
 MARKDOWN
 

sites/en/testing/additional_concepts.step renamed to sites/en/testing-rails-applications/additional_concepts.step

@@ -51,9 +51,7 @@ steps do
 
     message "On to controller tests! Just like the Orange model, you will create the OrangesController, which will also create spec files in the /spec/controllers folder of your app."
   end
-end
 
-steps do
   step do
     message "First, create the oranges controller and relevant spec files by typing this in the terminal:"