Rewrite base Class for sahara tests

Sahara clean_up methods and tearDown corrected
to properly remove data after run tests.
Fixed create nodegroup_templates and cluster_templates
for correctly work with/without autoassignment floating IP's.

Change-Id: I66922eee3d99e2754e089d01222c6053ed795347
Closes-Bug: #1311059
Closes-Bug: #1311554
Merge "Rewrite base Class for sahara tests"