Open Stack

A couple of teams have run into a problem with the
sphinxcontrib-pecanwsme extension emitting warnings which are then
treated as errors when the Sphinx flag warning-is-error is set to True.
For the time being, skip the step of setting that flag to True (but
still try to minimize the number of warnings in your doc build).

We could use some help resolving the warning, so if you're interested in
learning how sphinx extensions work ping me in #openstack-docs and I'll
try to get you started.

Doug