Starting since version 2.14, Nova automatically detects whether the
server data is on shared storage or not.
Removed 'on_shared_storage' parameter from nova evacuate call and
bumped nova api version from 2.9 to 2.14 so that shared storage
deployment can be detected by nova. Also added a related note in
README.rst to point out. Operators should configure shared storage
to use maskari otherwise instance data will be lost after evacuation.
Change-Id: I0b0581a5c84143fc91c9fc6e2c440096013c7438