Install a good version of pip in the venv.
Install a good version of pip in the venv.

Change-Id: If55032a5018b50cd7cc359ec4a013c8c18dc735e

openstack/networking-bigswitch,wolverineav/networking-bigswitch,wolverineav/networking-bigswitch,stackforge/networking-bigswitch,openstack/networking-bigswitch,stackforge/networking-bigswitch