Add first alembic version for db migration

Alembic provides command script to update a relational
database, using SQLAlchemy. I provide in this patchset the
initial version python script for create a Ocata db version.

Implements: blueprint db-migration

Change-Id: I7bda4286bc8141bb4fcfba3837070966ef506b5d

devstack/lib/watcher

@@ -188,7 +188,7 @@ function init_watcher {
         recreate_database watcher
 
         # Create watcher schema
-        $WATCHER_BIN_DIR/watcher-db-manage --config-file $WATCHER_CONF create_schema
+        $WATCHER_BIN_DIR/watcher-db-manage --config-file $WATCHER_CONF upgrade head
     fi
     create_watcher_cache_dir
 }