Exempt openstack-common from pep8 check
Exempt openstack-common from pep8 check

The openstack-common project already does its own pep8 checks; we
don't need to duplicate the effort.  This also avoids issues with
pep8 version skew between projects.

Change-Id: I50d6e1b21c743d811e44b415017ca7e19687c9c2

gkotton/vmware-nsx,gkotton/vmware-nsx