* On running tempest run -l, the ec2api-tempest-plugin is giving
ImportError: Start directory is not importable: '/tmp/.venv/
lib/python2.7/ec2api_tempest_plugin'. It is fixed by fixing
the test discovery path.
* Added lxml and tempest as a Requires for the plugin.
Change-Id: Ie64d0e96565980201143c0547c8b63513c883ea4