Mirdata

Compared to the 0.2.0.beta release, 0.2.0 includes:
* A PR template for new loaders
* bugfixes in jams converters
* exhaustive dataset tests
* descriptive assert messages in tests
* a generalized download_utils.downloader() function
* New dataset loaders:
* groove MIDI
* Maestro
* GiantSteps EDM key
* GiantSteps EDM tempo
* Beatport EDM key

This is the first beta release of the v0.2.X series.

Compared to 0.2.0a0 (alpha release), mirdata 0.2.0b0 has:
* a new utility function `jams_utils.notes_to_jams`, which converts notes annotations into JAMS format using note_to_midi from librosa. PR 186 by magdalenafuentes
* better support for remote data. PR 188 by rabitt
* addition of pysoundfile to the list of requirements. PRs 190 and 193 by lostanlen
* improvements to the documentation. PRs 194 and 201 by rabitt
* addition of a pull request template and updates to the contribution policy. PR 198 and 199 by magdalenafuentes
* a table of all supported datasets. PR 203 by rabitt
* a base `Track` class with unified `__repr__` implementation. PR 205 by rabitt

To consult the list of supported datasets, please visit:
https://mirdata.readthedocs.io/en/latest/source/datasets.html

To contribute a new dataset to mirdata, please visit:
https://github.com/mir-dataset-loaders/mirdata/blob/master/CONTRIBUTING.md

This is the first alpha release of the v0.2.X series.

Compared to v0.1, mirdata v0.2.0a0 has a new loader: TinySOL (165). TinySOL is a dataset of 2478 samples, each containing a single musical note from one of 14 different instruments.

Furthermore, rabitt has added a new data type in mirdata called `utils.MultipitchData`, which is compatible with mir_eval's `multipitch.evaluate` function. This addition fixes issue 101: "medleydb_melody melody3 type not in mir_eval format".

Lastly, magdalenafuentes made improvements to the documentation.

This version fixes a major bug in v0.1.0, related to the index of the RWC-Genre dataset.

As noted in issue 80, the file `indexes/rwc_genre.json` was incomplete: it contained had only 90 items instead of 100. More precisely, it lacked files RM-G09{i} for i in {1,..,9} and RM-G100. If these files were missing from `DATA_HOME`, or had invalid checksums, the function `mirdata.rwc_genre.validate` would have returned `({}, {})`, i.e. as if all files were present and valid. In other words, the validator of the mirdata.rwc_genre was too lenient. In the interest of reproducible usage, we recommend you to stop relying on the `mirdata.rwc_genre` module to validate the RWC-genre dataset.

For this reason, we have removed the `mirdata.rwc_genre` module entirely in v0.1.2.