activate the virtualenv manually before running the subshell
activate the virtualenv manually before running the subshell

appears to not cause any problems — might solve some.

Signed-off-by: Kenneth Reitz <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@kennethreitz.org>

nateprewitt/pipenv,kennethreitz/pipenv