Major changes:
* Released MineRLObtainDiamondVectorObf-v0 (and other obfuscated environments for the competition! See http://minerl.io/)
* Released new V3 dataset containing both obfuscated and standard env data.
* Internally refactored the MineRL API to use env handlers.
* Unified the data publishing and environment specification API
* Forced all spaces to return Numpy arrays and scalars.
* Open sourced the data publishing pipeline
* Added forbidden streams to the data pipeline
* Rewrote the MineRL viewer to be extensible and support rendering for competition streams
* Rehosted the data on S3, drastically increasing
* Made Asia and Europe mirrors for the dataset.
* Made new MineRL download method (supports sharding and mirrors)