* Added histogram functionality to custom metrics infrastructure (another tab in tensorboard)
* updated example to include histogram metric
* added histograms to TBXLogger
* add episode rewards
* lint
Co-authored-by: Eric Liang <ekhliang@gmail.com>
* modify tf_policy to enable EntropyCoeffSchedule to handle list, and avoid negative values under current implementation
* Update custom_metrics_and_callbacks.py
* Update tf_policy.py