* Add `RandomEnv` example to examples folder.
Convert warning into Error message when using an LSTM in a non-shared-vf network (after the warning, the program would crash).
* LINT.
* Fix issue #6884. LSTM + non-shared vf NN + PPO crashes when using a Tuple action space.
* LINT
* Change warning message for Model: shared_vf=False, LSTM=True cases.
* Bug fix.
* Add examples/random_env.py test to Jenkins.