title: How to use a specific build of Python in my virtual environment
body: <p>I am trying to create a virtual environment with a specific build of python (specifically, 3.6.7) to develop locally because I am pushing my code to a Heroku stack which only supports this version of Python 3 ( see <a href="https://devcenter.heroku.com/articles/python-support#specifying-a-python-version" rel="nofollow noreferrer">here</a> ).</p>
  
  <p>As I understand it, this specific build of python must already be installed on my machine so I can do something like <code>virtualenv --python=/path/to/python3.6.7 env_directory</code>. My questions are:</p>
  
  <ol>
  <li>What is the easy way to install Python-3.6.7 on both Ubuntu and OSX (I will be developing in both operating systems)?</li>
  <li>Is there some virtual environment tool out there that can download a specific build automatically?</li>
  </ol>