Add source field to Meter model

Just like Sample model, we should also add source field to
Meter model to identify where the meter comes from.

Change-Id: I2381d67f84692bfc7d167c2b0d90bfa32b845f00
Fixes: Bug #1225583
Adding region name to service credentials

Change-Id: Ic6515e8e1c4f12a3a7381d99bebd30db54d9385d
Closes-Bug: #1227146
Don't send unuseful rpc alarm notification

If the alarm have no actions for the new state we don't need to send a
message through the rpc for notification, just log a debug message
when it occur.

Fixes bug 1224416

Change-Id: I9aeb01e936dbacfbabb06e8b408d5ee04a93cb34
Require oslo.config 1.2.0 final

Now that 1.2.0 has been released, require it rather than one of the beta
release tarballs.

Closes-Bug: #1182861
Change-Id: I75ffc4a572d14488d19491a38742d6920951c171
Merge "Don't send unuseful rpc alarm notification"
Merge "Require oslo.config 1.2.0 final"
Merge "Add source field to Meter model"
Merge "Adding region name to service credentials"