Use virtualenv for installation of OpenStack projects and
dependencies to avoid conflicts with Python libraries installed
by non-OpenStack binary packages.
Change-Id: I21ecd673b2e93335b1d3dd4e279e940c9d694c3c
Implements: blueprint virtualenv
Updated build.py to reflect this change.
Deprecate --template option and make it a noop.
Change-Id: I7cd98d1ee684a4c64984a49597159868152683b2
Partially-Implements: blueprint remove-docker-dir