Unittests for binarized reward #87
Description
For some RL tasks, it is more important to know that there is a non-null reward rather than knowing its magnitude.
The BinarizeReward transforms makes all rewards either 1 (non-negative) or 0 (null or negative).
This class is currently not tested. The test should include (1) testing that the output rewards match what is expected (2) test that the reward_spec environment attribute is modified accordingly (should be of type BinaryDiscreteTensorSpec).