* GraphManager.set_session also sets self.sess
* make sure that GraphManager.fetch_from_worker uses training phase
* remove unnecessary phase setting in training worker
* reorganize rollout worker
* provide default name to GlobalVariableSaver.__init__ since it isn't really used anyway
* allow dividing TrainingSteps and EnvironmentSteps
* add timestamps to the log
* added redis data store
* conflict merge fix
* Integrate coach.py params with distributed Coach.
* Minor improvements
- Use enums instead of constants.
- Reduce code duplication.
- Ask experiment name with timeout.
