title: inconsistent pip version in PyCharm
body: <p>I'm using PyCharm on Windows. I have a project setup for small experiments with algorithms that uses it's own virtual environment. I was trying to install tensorflow and I got an error that I'm running pip 10.0.1 and should upgrade to 18.1, which I did through "File/Settings/Project Interpreter". It now says 18.1. But I'm still getting warnings about using version 10.0.1.</p>
  
  <p><a href="https://i.stack.imgur.com/w6BbP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/w6BbP.png" alt="different version of pip"></a></p>
  
  <pre><code>(venv) C:\users\xxx\pycharmprojects\so&gt; pip list
  ...
  pip            10.0.1
  You are using pip version 10.0.1, however version 18.1 is available.
  You should consider upgrading via the 'python -m pip install --upgrade pip' command.
  
  (venv) C:\users\xxx\pycharmprojects\so&gt;python -m pip install --upgrade pip
  Requirement already up-to-date: pip in c:\users\xxx\pycharmprojects\so\venv\lib\site-packages (18.1)
  
  (venv) C:\users\xxx\pycharmprojects\so&gt; pip list
  ...
  pip            10.0.1
  You are using pip version 10.0.1, however version 18.1 is available.
  You should consider upgrading via the 'python -m pip install --upgrade pip' command.
  
  (venv) C:\users\xxx\pycharmprojects\so&gt;python -m pip list
  ...
  pip            18.1
  </code></pre>