title: How do I upgrade lein in Ubuntu OS?
body: <p>I am on Ubuntu 14.04.2 LTS.</p>
  
  <p>I want to run LightTable (downloaded from the <a href="https://github.com/LightTable/LightTable" rel="nofollow">official GitHub website</a>). When I run the script, it says that I need <a href="http://leiningen.org/" rel="nofollow">leiningen</a>.</p>
  
  <p>I installed leiningen using <code>apt-get install leiningen</code>. It worked fine.</p>
  
  <p>Now it says that I need a more recent version: "Do a lein upgrade first".</p>
  
  <p>How do I upgrade lein?</p>