title: Update a package by easy_install
body: <p>I'm new to python. I would like to install the latest version of mitmproxy(0.17.1). The current version installed on the system is 0.15. When I do </p>
  
  <pre><code>easy_install -U mitmproxy 
  </code></pre>
  
  <p>It says:</p>
  
  <pre><code>Reading https://pypi.python.org/simple/mitmproxy/
  Best match: mitmproxy 0.15
  Processing mitmproxy-0.15-py2.7.egg
  mitmproxy 0.15 is already the active version in easy-install.pth
  </code></pre>
  
  <p>So it can not find the latest version and when I do:</p>
  
  <pre><code>easy_install  'mitmproxy==0.17.1'
  </code></pre>
  
  <p>I get :</p>
  
  <pre><code>No local packages or download links found for mitmproxy==0.17.1
  </code></pre>
  
  <p>Why can't it find the latest version? What should I do to install the latest one?</p>