Remove virtualenv management scripts from oslo-incubator

This commit removes the old virtualenv management scripts from oslo
incubator. They were just wrappers around virtualenv and don't really
work well in a world with global requirements and constraints. This
commit just removes them since there isn't any reason to keep them
around.

Change-Id: Ib7dd6b34533880e48b367732ae3520026a92500e
4 files changed