title: Install Error: 'rubygems' has no installation candidate
body: <p>Hi I would appreciate some help installing rubygems. This is what happens when I try. "ruby-full" has already been installed. How do I fix this? What is the issue?</p>
  
  <pre><code>$ sudo apt-get install rubygems 
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  Package rubygems is not available, but is referred to by another package.
  This may mean that the package is missing, has been obsoleted, or
  is only available from another source
  However the following packages replace it:
    ruby
  
  E: Package 'rubygems' has no installation candidate
  </code></pre>
  
  <p>I am running Ubuntu 14.04. Ruby version installed: 1:1.9.3.4. Please let me know if there are any other additional details that could help solve this issue.</p>