title: RSpec error "Uninitialized constant FactoryGirl (Name Error)"
body: <p>I try running my RSpec test:</p>
  
  <pre><code>rspec comments.rb
  </code></pre>
  
  <p>but keep getting the same error (see title). Before anyone asks I have already added <code>require factory_girl</code> to spec_helper.rb.</p>
  
  <p>The contents of <code>spec/factories/comments.rb</code> file are:</p>
  
  <pre><code>  FactoryGirl.define do
      factory :comment do
        comment "MyString"
        task_id 1
    end
  end
  </code></pre>
  
  <p>Here is testing group of the gemfile where I included factory_girl_rails:</p>
  
  <pre><code>source 'http://rubygems.org'
  
  ...
  
  group :development, :test do
    gem 'debugger'
    gem 'factory_girl_rails'
    gem 'rspec-rails'
  end
  
  ...
  </code></pre>