change pylint wrapper to let messages be prefixes
change pylint wrapper to let messages be prefixes

The messages for many of the errors reported by pylint have been
extended to include "suggestions" (especially in the case of undefined
variables or members). Rather than update all of the individual
messages in the configuration file, just treat the messages as
prefixes.

Change-Id: I1f11c50e39dbd43c4a9b54ccaaccf03f5ff07aca
Signed-off-by: Doug Hellmann <0798ebecfb7bc4dfb9d0445c2fa030eb64e1fa1c@doughellmann.com>

openstack/trove,openstack/trove