Currently, bootstrap-ansible.sh fails to run as $PIP_INSTALL_OPTIONS is
surrounded by quotations which get-pip.py does not like. This commit
simply removes those so get-pip.py will install pinned packages
correctly.
This was not caught in the gate check as the gate image already has
pip installed. This bug would only be encountered on a fresh build
without pip installed.
Change-Id: I9b9033a065c8b878ac129b8d4b99f3d6874fd6ff