Use local apt and pypi mirror for tripleo-cd

More fast is faster. Much vrooom. pip-cache is not concurrency-safe,
so remove that, and pypi-openstack is subject to network vaguaries,
which is why I'm bringing the mirror in.

Change-Id: I994e3939fb0db8029185f1674759ebfa92307e57
Merge "Use local apt and pypi mirror for tripleo-cd"