title: Vagrant : RuntimeError: Python version >= 3.5 required
body: <p>I am trying to run these codes: 
  <a href="https://github.com/cndreisbach/call-for-service/blob/master/docs/src/development.md" rel="nofollow noreferrer">https://github.com/cndreisbach/call-for-service/blob/master/docs/src/development.md</a></p>
  
  <p>I have been updating my python and made my default version of python 3.5 </p>
  
  <pre><code>vagrant@cfs:/vagrant$ python --version
  Python 3.5.7
  </code></pre>
  
  <p>When i run : <code>sudo pip3 install -r requirements.txt</code></p>
  
  <pre><code>    Cleaning up...
      Command python setup.py egg_info failed with error code 1 in /tmp/pip_build_root/pandas
      Storing debug log for failure in /home/vagrant/.pip/pip.log
   RuntimeError: Python version &gt;= 3.5 required.
  </code></pre>
  
  <p>How I can fix that issue? </p>