* Refactor gym envs to support dynamic arguments
* Fix viewer setup lookat configuration
* Add xml_file argument for mujoco envs
* Move refactored mujoco envs to their own _v3.py files
* Revert "Add xml_file argument for mujoco envs"
This reverts commit 4a3a74c00da73662c10c3256fb7242b85271539c.
* Revert "Fix viewer setup lookat configuration"
This reverts commit 62b4bcffea9d63bdd1eb6580d4fda9893fa20cdf.
* Revert "Refactor gym envs to support dynamic arguments"
This reverts commit b2a439f74f8be390c806515f77849e04776f91bb.
* Fix v3 SwimmerEnv info
* Regiter v3 mujoco environments
* Implement v2 to v3 conversion test
* Add extra step info the v3 environments
* polish the new unit tests a little bit
