Updated from global requirements

Change-Id: Ibca24abb665e28ebcb2010d036467c3cec7c7541
Add -U to pip install command in tox.ini

Ask pip to upgrade packages in the virtualenv so that a long-lived
virtualenv is still kept up to date as external dependencies change.

Change-Id: Id1e83aa5dd7c39d4827baeb39827b0ddeb8b6d4a
Merge "Add -U to pip install command in tox.ini"
Merge "Updated from global requirements"