Martin von Zweigbergk <martinvonz@google.com> [Thu, 09 Mar 2017 08:33:00 -0800] rev 2067
setup.py: remove unused and harmful code importing mercurial
This was failing on some build system we have. The import seemed to
succeed, but then mercurial.__all__ would fail. I don't know why, but
since it's unused anyway, let's just drop it.