Add generaton cli entrypoint

example/client.py

@@ -0,0 +1,4 @@
+"""Echo client."""
+
+if __name__ == "__main__":
+    pass

example/schema.proto

@@ -0,0 +1,9 @@
+syntax = "proto2";
+
+message EchoMsg {
+  required string value = 1;
+}
+
+service Example {
+  rpc Echo (EchoMsg) returns (EchoMsg) {}
+}

example/server.py

@@ -0,0 +1,4 @@
+"""Echo server."""
+
+if __name__ == "__main__":
+    pass