If we're installing pip/virtualenv from source, we need to make sure
we pre-install the packaged versions before the upstream
versions. Otherwise, CI jobs later on that depend on packaged versions
of pip/virtualenv can bring them in and overwrite the upstream
versions we have installed, which leads to a heck of a mess and
usually very confusing failures.
I have also moved in a small hack from system-config:install_puppet.sh
that we found was necessary when using pip versions from upstream.
Note this is not as much of an issue on Debian/Ubuntu, as they keep
their pip packages in a separate place to the system packages, so you
don't have these overwite conflicts as much.
Change-Id: Ib40708c07b939b84661c44df88a5a308fd0c7216
a85ce75d6b