title: Direct link to github in requirements.txt while using conda
body: <p>There is syntax used in requirements.txt that allows dependencies from a github project (<a href="https://stackoverflow.com/questions/16584552/how-to-state-in-requirements-txt-a-direct-github-source">see here</a>).
  I want to work with conda and keep requirements file compatible with pip (for others), so I don't want to use yml environment files.</p>
  
  <p>Is there a way to create a file that both pip and conda could install from?</p>