Cleanup README.rst

There are two harmless typos in the README.rst
'OpenStackclient' => 'OpenStack Client'
'python-*client' => the '*' is being interpreted as a link

Change-Id: Ie813e220c3c150f46edb2c93f94e8bb78bdb0013
Closes-Bug: #1350518
Merge branch 'ksc-session' into dt-test
Merge branch 'compute-test-fix' into dt-test