Updated openstack/openstack
Project: openstack/tempest  c240bccc9173261805f9513d2428a2bb162a9326

Change rest client exceptions' inheritances

RateLimitExceeded, ServerFault and OverLimit raise at rest_client layer
and they should inherit from RestClientException for representing what
happens clearly. This patch changes them.

Change-Id: I0b74bd44a88cc68bdaeab6bd605722d47f5a28a9