Replace deprecated keystoneclient...exceptions
Replace deprecated keystoneclient...exceptions

Use "keystoneclient.exceptions" instead of the deprecated
"keystoneclient.openstack.common.apiclient.exceptions".

ref: https://github.com/openstack/python-keystoneclient/blob/master/
keystoneclient/openstack/common/apiclient/exceptions.py#L25

Change-Id: I4855d0602529b4b3ff3acbdb257e8116acc66542

stackforge/solum,stackforge/solum,devdattakulkarni/test-solum,openstack/solum,devdattakulkarni/test-solum,openstack/solum