title: pyvenv not working because ensurepip is not available
body: <p>I upgraded from ubuntu 14.04 to ubuntu 16.04 a few days ago.
  When I try to create a virtual env by using</p>
  <pre><code>pyvenv .venv
  </code></pre>
  <p>or</p>
  <pre><code>python3 -m venv .venv
  </code></pre>
  <p>There is an error:</p>
  <pre><code>The virtual environment was not created successfully because ensurepip is not
  available.  On Debian/Ubuntu systems, you need to install the python3-venv
  package using the following command.
  
      apt-get install python3-venv
  
  You may need to use sudo with that command.  After installing the python3-venv
  package, recreate your virtual environment.
  
  Failing command: ['/home/user/.venv/bin/python3.5', '-Im', 'ensurepip', '--upgrade', '--default-pip']
  </code></pre>
  <p>I tried running both</p>
  <pre><code>sudo apt-get install python3-venv
  </code></pre>
  <p>and</p>
  <pre><code>sudo apt-get install python3.5-venv
  </code></pre>
  <p>but it did not solve my problem.</p>