Add License headers to all code files

This was related to bug 547
https://osm.etsi.org/bugzilla/show_bug.cgi?id=547

Change-Id: Ief72f6e3b3de828be033729298ae905d163c6988
Signed-off-by: Dominik Fleischmann <dominik.fleischmann@canonical.com>
diff --git a/tests/charms/layers/broken/metadata.yaml b/tests/charms/layers/broken/metadata.yaml
index 1780d3f..ed41942 100644
--- a/tests/charms/layers/broken/metadata.yaml
+++ b/tests/charms/layers/broken/metadata.yaml
@@ -1,3 +1,17 @@
+#  Copyright 2019 Canonical Ltd.
+
+#  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.
+
 name: broken
 summary: A (broken) simple VNF proxy charm
 maintainer: Adam Israel <adam.israel@canonical.com>