Add LICENSE file.
Add LICENSE file.

Change-Id: I3908c09085f5e79c9f00b932131b1e64f1fc250b

GoogleCloudPlatform/appengine-sidecars-docker,oierw/appengine-sidecars-docker,kmbarry1/appengine-sidecars-docker,oierw/appengine-sidecars-docker,kmbarry1/appengine-sidecars-docker,kmbarry1/appengine-sidecars-docker,GoogleCloudPlatform/appengine-sidecars-docker,oierw/appengine-sidecars-docker,oierw/appengine-sidecars-docker,kmbarry1/appengine-sidecars-docker