Ephemeral volume support

This feature enables reddwarf to create instance and run mysql on ephemeral disk.
To enable this feature, set the flag "reddwarf_volume_support to False and specify the device_path and mount_point variables.

Also added int tests for ephemeral support

fixes LP bug# 1175719
BP: https://blueprints.launchpad.net/reddwarf/+spec/ephemeral-storage-volume

Change-Id: I869297e7da288ac42b359c8cdb731e8b7281d51b
Merge "Ephemeral volume support"