Combined commit with code improvements, fixes, pep8 and rearrangements

* Additional unit tests for routing_svc_helper
* Flake8/pep8 fixes
* Also modified pprint to pformat in agent-state-logging
* Improved comments
* Rename services_api to devicedriver_api and move it to device_driver folder
* Removed service_helper.py

Change-Id: Idbafdfea23fc9622a1219818d90013f03ce3e8d5