title: Rails 5 entity path helpers method not found
body: <p>After upgrading to Rails 5.0.0.beta4, I get an 'undefined method' error when trying to send an email using the Rails path helpers.  I have an ActiveRecord class called <code>Project</code> and I am trying to send an email containing a link to the projects page using the path helper `project_path(project.id).  Prior to Rails 5 this used to work.</p>
  
  <p>Here is the ERB for the link:</p>
  
  <pre><code>&lt;%= project_path(@project.id) %&gt;
  </code></pre>
  
  <p>I'm using ActionMailer to send the email.  Any ideas on what might have caused this problem after switching to Rails 5?</p>