Revert "Revert "Merge pull request #492 from techalchemy/pypi-hash-retrieval""
Revert "Revert "Merge pull request #492 from techalchemy/pypi-hash-retrieval""

This reverts commit 8e0c834e909bf3386186bfd7d310b25bf81ce2cc.

nateprewitt/pipenv,kennethreitz/pipenv