chore: add synth.py file (#14)

Fixes #10

synth.py

@@ -0,0 +1,24 @@
+# Copyright 2019 Google LLC
+#
+# 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.
+
+"""This script is used to synthesize generated parts of this library."""
+
+import synthtool as s
+import synthtool.gcp as gcp
+
+
+templates = gcp.CommonTemplates().java_library()
+s.copy(templates, excludes=[
+    'README.md',
+])