Do not check requirements when loading plugins
Do not check requirements when loading plugins

Turn off the setuptools requirements check when loading plugins to avoid
errors with code that works but where the package metadata makes
setuptools think it might not.

Change-Id: I0b15d3a8d311f0ad988c16758cec32280c83eb7e
Related-bug: #1446847

idjaw/cliff,enzochiau/cliff,openstack/cliff,openstack/cliff,idjaw/cliff,enzochiau/cliff,dtroyer/cliff,dtroyer/cliff