Silence urllib3 redundant logging.

This patch makes the default logging level of heat-keystone-setup-domain
to be WARNING and the 'urllib3.connectionpool' logging level to be
WARNING as well.

The intent is to remove unncecessary logging information from urllib3
library.

Closes-Bug: 1358093
Change-Id: I650e80aa1093c8c7e7c5dac3694d58139d2ec260
Merge "Silence urllib3 redundant logging."