Updated README
Updated README

Updated README to include references to Swift and Glance
which were missing.

Change-Id: I0dcfb4615b39ce1b27995c99939f57da850815ba
Closes-Bug: #1525608

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