Add Goal in BaseStrategy + Goal API reads from DB

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

watcher/cmd/decisionengine.py

@@ -28,6 +28,7 @@ from oslo_service import service
 from watcher._i18n import _LI
 from watcher.common import service as watcher_service
 from watcher.decision_engine import manager
+from watcher.decision_engine import sync
 from watcher import version
 
 LOG = logging.getLogger(__name__)
@@ -41,6 +42,9 @@ def main():
     LOG.info(_LI('Starting Watcher Decision Engine service in PID %s'),
              os.getpid())
 
+    syncer = sync.Syncer()
+    syncer.sync()
+
     de_service = watcher_service.Service(manager.DecisionEngineManager)
     launcher = service.launch(CONF, de_service)
     launcher.wait()