SEBA-497 delayering, Makefile, and tox for onos-synchronizer

Change-Id: I849b307330a6fd5a5de5489d8f2db804a02acead
diff --git a/xos/synchronizer/event_steps/__init__.py b/xos/synchronizer/event_steps/__init__.py
new file mode 100644
index 0000000..19d1424
--- /dev/null
+++ b/xos/synchronizer/event_steps/__init__.py
@@ -0,0 +1,13 @@
+# Copyright 2019-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.