* Extend confd test case to test for env var propagation
* Env vars set in conf.d files are expected to propagate
* Lock needs to be acquired when instantiating script
* Retry on lock being unavailable
* Refactor locking to return plain error
* Collect LockedTime in stats
* Add test case
* Add documentation for LOCK_TIMEOUT
* Log in case lock needs to be awaited
* Release resources created for awaiting lock