javelin: create and attach volumes

Bring Cinder support in tempest/javelin to test:
- volume creation
- volume attachement to a server

Partial-Bug #1330178
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>

Change-Id: Ie0e437312aab3ccb0d8233e4b73f9215f64149ac
Update config generator from oslo-incubator

This commit pulls in the latests version of the config generator from
oslo.

Change-Id: I3a2b06dd9ca3285a3d93298ea5727b705f6109e4
Use config generator rc instead of wrapper script

This commit removes the generate_sample wrapper script and adds an
rc file for the config generator to specify the alternate path.
This makes console messages from the generator tooling point
consistent with what is actually being used. Before because a wrapper
was used error messages would recommend running the incorrect tool.

Change-Id: I0ac792454777af6e3f1d718836031f9a14850229
Merge "Update config generator from oslo-incubator"
Merge "Use config generator rc instead of wrapper script"
Merge "javelin: create and attach volumes"
Merge branch 'master' of https://github.com/openstack/tempest