com.unity.ml-agents 1.2.0-preview Package Notes

#### com.unity.ml-agents (C#)
Fixed an issue where RayPerceptionSensor would raise an exception when the
list of tags was empty, or a tag in the list was invalid (unknown, null, or
empty string). (#4155)
#### ml-agents / ml-agents-envs / gym-unity (Python)
Fixed an error when setting `initialize_from` in the trainer confiiguration YAML to
`null`. (#4175)
Fixed issue with FoodCollector, Soccer, and WallJump when playing with keyboard. (#4147, #4174)
Fixed a crash in StatsReporter when using threaded trainers with very frequent summary writes
(#4201)
`mlagents-learn` will now raise an error immediately if `--num-envs` is greater than 1 without setting the `--env`
argument. (#4203)

com.unity.ml-agents 1.2.0-preview