Change migrates the monasca-api to use oslo-config-generator in
order to always build newest configuration file. That removes
the need of maintaning the file along with changes to oslo configuration.
The example of the file is also included in the documentation.
Also:
* ported case for launching api under WSGI and allowing the argument
parsing of oslo to take place
Story: 2000970
Task: 4865
Story: 2000964
Task: 4106
Change-Id: I57547b0e2122e40f58db5f949773900b76214526