In this changeset, I changed the Strategy base class to add new
abstract class methods. I also added an abstract strategy class
per Goal type (dummy, server consolidation, thermal optimization).
This changeset also includes an update of the /goals Watcher API
endpoint to now use the new Goal model (DB entries) instead of
reading from the configuration file.
Partially Implements: blueprint get-goal-from-strategy
Change-Id: Iecfed58c72f3f9df4e9d27e50a3a274a1fc0a75f