Revert "Be more agressive trying to install requirements."

This reverts commit f4ed0c3120852c2a59af8ebc4fdf657672787d67
Upgrade pip and setuptools in the mirror venv

Older pip does not process transitive dependencies properly. To ensure
that 3rd level transitive depends get processed by run-mirror, ensure
that we have current pip in our mirror build environment.

Without upgrading setuptools, we can hit the transitive depend problem.

Change-Id: I4a4611109ed9b35dea2efc00583ab69ebc1a39ba
Merge "Revert "Be more agressive trying to install requirements.""
Merge "Upgrade pip and setuptools in the mirror venv"