[shade] Simplify and optimise the shade role
[shade] Simplify and optimise the shade role

The shade role currently installs pip and virtualenv
into user space and tries to use that to create a
virtualenv for shade. This is an extremely messy way
of going about setting up a venv.

We simplify it all by using the distribution's
virtualenv package to get virtualenv installed, then
setting up the venv without updating pip, setuptools
and wheel inside it. By doing this we get a stable
virtualenv.

Once that's all done, we can install openstacksdk into
the venv without any further drama.

Change-Id: I19e9bcccc56d359636d4f470323fe6133282b049

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared