title: will_paginate helper undefined in sinatra with mongoid
body: <p>I am using sinatra 1.4.3 and mongoid 3.1.4. I tried adding will_paginate gem from master branch for mongoid support so I added this to my gemfile:</p>
  
  <pre><code>gem 'will_paginate', :git =&gt; 'git://github.com/mislav/will_paginate.git', 
                       :branch =&gt; 'master'
  </code></pre>
  
  <p>In environment.rb I added:</p>
  
  <pre><code>require 'will_paginate'
  require 'will_paginate/mongoid'
  </code></pre>
  
  <p>And pagination method started working. I have still problem with will_paginate helper. In my views I get errors like:</p>
  
  <pre><code>NoMethodError: undefined method `will_paginate' for #&lt;Class:0x006ff5df8578b0&gt;
  </code></pre>
  
  <p>Am I missing something for helper to work under sinatra?</p>