Merge pull request librosa#918 from librosa/070-release-final

0.7.0 release prep

Merge pull request librosa#910 from librosa/070-release

0.7.0 release preparation

Merge pull request librosa#809 from librosa/063-release-prep

0.6.3 release preparation

0.6.2 docs and version update

updated doi badge [ci skip]

Merge pull request librosa#718 from librosa/061-release-prep

0.6.1 release prep

updated version and changelog for 0.6.0 release [ci skip]

updated changelog and version for 0.6rc1 [ci skip]

Merge pull request librosa#668 from librosa/doc-update-0.6

Doc update 0.6

updated author list