Change the API of oslo.service to accept conf object and
remove usage of global CONF object throughout the library.
List of functions/classes that accept conf as a parameter:
1. eventlet_backdoor.py
* initialize_if_enabled
2. periodic_task.py
* PeriodicTasks
3. service.py
* launch
* ServiceLauncher
* ProcessLauncher
4. sslutils.py
* is_enabled
* wrap
Fixed the unit tests.
APIImpact
bp graduate-oslo-service
Change-Id: Icbd5f9e386b0eee2f7c60a65c076f53ba5f0f637
856a653cbf