title: Specify a plugin as gem from github in Gemfile
body: <p>I am including 'acts_as_rateable' gem in my Gemfile like this</p>
  
  <pre><code>gem 'acts_as_rateable', :git => 'git://github.com/azabaj/acts_as_rateable.git'</code></pre>
  
  <p>and then when I do <code>bundle install</code> it gives me this error message!</p>
  
  <blockquote>
    <p>Could not find gem 'acts_as_rateable
    (>= 0, runtime)' in
    git://github.com/azabaj/acts_as_rateable.git
    (at master). Source does not contain
    any versions of 'acts_as_rateable (>=
    0, runtime)'</p>
  </blockquote>
  
  <p>I am developing a plugin of my own, when I include that, even that gives the same error like this..</p>
  
  <p>I assume this has something to do with the gemspec?</p>
  
  <p>Please help</p>
  
  <p>Rails version : 3.0.1
  Rubygems version : 1.3.7
  Bundler version : 1.0.3</p>
  
  <p>let me know if you need any other details..</p>