title: Add a custom wheel file as a dependency in setup.py?
body: <p>I'm working on a project where one of the dependencies is actually a <code>.whl</code> that isn't on pypi (i.e. I had to download the wheel direct from the author and <code>pip</code> install it directly). In my <code>setup.py</code> file, is there a way to do something like:</p>
  
  <pre><code>install_requires=[
      'library.whl',
      'matplotlib==2.2.2',
      'numpy==1.14.2',
      'opencv-python==3.4.0.12',
      'Pillow==5.1.0',
      'PyYAML==3.12',
  ],
  </code></pre>
  
  <p>Or something along these lines since its not on pypi (and I would just add the <code>library.whl</code> in the <code>MANIFEST.in</code> file or something)? If not, is there a recommended way to do this for this type of situation? I'd ideally like to solve this in the <code>setup.py</code> file so I can install my library easily with a single <code>pip install</code></p>