Move meter signature computing into meter_publish

Blueprint: oslo-multi-publisher

Change-Id: I7e758dfb56604fb5a92690ac9719b129837159cf
Signed-off-by: Julien Danjou <julien@danjou.info>
Use jsonutils instead of json in test/api.py

Also remove the then unused json import

Change-Id: I5570981e04487301c1bf723c04b266fc445aed1e
Fix the nova notifier tests after a nova rename

https://github.com/openstack/nova/commit/3222d8bb021effb3156ed86e263cdc0ac64fd44a

fixes bug 1178055

Change-Id: I49f530a73c70a3efbec000e5de493b0d82ad3435
Merge "Move meter signature computing into meter_publish"
Merge "Use jsonutils instead of json in test/api.py"