Update python-saharaclient to 0.7.6 version

The updated version contains the following
new functionality:
* keystone v3 CLI
* support for filtering list() calls
* unit tests for python bindings

Change-Id: I3bec5236d9db846aa3ffb311015018729d3735a0
Merge "Update python-saharaclient to 0.7.6 version"