title: Error: Command 'test' not recognized
body: <p>Im developing in c9.io in a rails server. I execute 
  <code>rails test</code> and it works corectly. Next day I execute the same command but instead appear Error: Command 'test' not recognized I do not change anything. How can I restore this command?  </p>
  
  <p>Note:<code>rake test</code> works perfectly but ruby page <a href="http://edgeguides.rubyonrails.org/testing.html" rel="noreferrer">http://edgeguides.rubyonrails.org/testing.html</a> and ruby on rails tutorial by Michael Hartl <a href="https://www.railstutorial.org/book/static_pages" rel="noreferrer">https://www.railstutorial.org/book/static_pages</a> talk about rails test command and it work for me 2 days.</p>
  
  <p>this is my gemfile</p>
  
  <pre><code>source 'https://rubygems.org'
  
  gem 'rails',        '4.2.2'  
  gem 'sass-rails',   '5.0.2'  
  gem 'uglifier',     '2.5.3'  
  gem 'coffee-rails', '4.1.0'  
  gem 'jquery-rails', '4.0.3'  
  gem 'turbolinks',   '2.3.0'  
  gem 'jbuilder',     '2.2.3'  
  gem 'sdoc',         '0.4.0', group: :doc
  
  
  group :development, :test do    
  gem 'sqlite3',     '1.3.9'    
  gem 'byebug',      '3.4.0'    
  gem 'web-console', '2.0.0.beta3'    
  gem 'spring',      '1.1.3'
  end
  
  
  group :test do    
  gem 'minitest-reporters', '1.0.5'    
  gem 'mini_backtrace',     '0.1.3'    
  gem 'guard-minitest',     '2.3.1'   
  end
  
  
  group :production do      
  gem 'pg',             '0.17.1'      
  gem 'rails_12factor', '0.0.2'  
  end
  </code></pre>