Change upgrades the monasca-notification to leverage
the capabilities of both oslo.log and oslo.conf:
- configuration of logging separated from application settings
- ability to enforce data types for application settings
- ability to use oslo.config-generator capabilities
- automatic configuration parsing done by oslo.cfg
That change will bring it closer to the rest of monasca
components where such transition has happened already.
However, in the rest of monasca, oslo.cfg was partially
or fully implemented whereas monasca-notification has
been relying on YAML based configuration file.
Therefore backward compatybility for such format will
be kept for now.
Story: 2000959
Task: 4093
Task: 4092
Change-Id: Ia75c3b60d0fada854178f21ca5ccb9e6a880f37f
e1a9b9a96a