title: error: command 'cmake' failed: No such file or directory
body: <p>Getting error while installing vaex in Pycharm with Python3.8
  I have installed below before running this on my Win-10 64-bit:</p>
  
  <pre><code>- cmake v3.15.3
  - pep517 v0.8.1
  - pip v19.3.1
  </code></pre>
  
  <p>Error logs:</p>
  
  <pre><code>running build_ext
  creating build\temp.win-amd64-3.8
  creating build\temp.win-amd64-3.8\Release
  -- Running cmake for pyarrow
  cmake -DPYTHON_EXECUTABLE=C:\Users\xxxxx\AppData\Local\Programs\Python\Python38\python.exe  -G "Visual Studio 14 2015 Win64" -DPYARROW_BOOST_USE_SHARED=on -DCMAKE_BUILD_TYPE=release C:\Users\xxxxx\AppData\Local\Temp\pip-install-g3tufyo5\pyarrow
  error: command 'cmake' failed: No such file or directory
  ----------------------------------------
  ERROR: Failed building wheel for pyarrow
  ERROR: Could not build wheels for pyarrow which use PEP 517 and cannot be installed directly.
  </code></pre>
  
  <p>Any idea, what I am missing?</p>