title: Rails: Flash Messages not appearing anywhere
body: <p>So let's say I have code like this:</p>
  
  <pre><code>class PostsController &lt; InheritedResources::Base 
    # Add before_filter here and devise should handle the redirection if the user is not signed in.
    before_filter :authenticate_user!, only: [:vote_up]
  
    def vote_up
    begin
    current_user.vote_for(@post = Post.find(params[:id]))
    redirect_to [@post]
    flash[:success] = "You have voted successfully"
  rescue ActiveRecord::RecordInvalid
    redirect_to [@post]
    flash[:error] =  "You have already voted"
    end
   end
  
  end
  </code></pre>
  
  <p>Neither of the messages "You have voted successfully" or "You have already voted" are being shown.</p>
  
  <p>In my view I have: </p>
  
  <pre><code>enter code here
  
  &lt;p id="notice"&gt;&lt;%= notice %&gt;&lt;/p&gt;
      &lt;%= @post.embed .html_safe %&gt;
      &lt;header&gt;
          &lt;h7&gt;&lt;%= @post.name %&gt;&lt;/h7&gt;
      &lt;/header&gt;
  &lt;h8&gt;&lt;%= @post.title %&gt;&lt;/h8&gt;
  &lt;article&gt;
  &lt;%= @post.content .html_safe %&gt;
  
  &lt;p&gt;
  &lt;%= link_to 'Back', posts_path %&gt; |
  &lt;%= link_to('Vote for this song!', vote_up_post_path(@post), :method =&gt; :post) %&gt;&lt;/p&gt;
  
  &lt;p&gt;&lt;id="notice"&gt;&lt;%= notice %&gt;&lt;/p&gt;
  </code></pre>
  
  <p>No dice. I'm still not getting flash messages anywhere. Any idea what I'm doing wrong?</p>