Merge pull request streamlink#1757 from beardypig/release-0.13.0-fix

scripts: fix bug in the release for generating the CHANGELOG

Merge pull request streamlink#1644 from cdrage/release-0.12.1

0.12.1 Release

Merge pull request streamlink#1560 from piddubnyi/liverussiatv

plugins.live_russia_tv New Plugin implementation for live.russia.tv

Merge pull request streamlink#1537 from cdrage/release-0.11.0

0.11.0 Release

Merge pull request streamlink#1449 from cdrage/release-0.10.0

0.10.0 Release

Merge pull request streamlink#1330 from cdrage/release-0.9.0

0.9.0 Release

Merge pull request streamlink#1215 from cdrage/release-0.8.1

0.8.1 Release

Merge pull request streamlink#1050 from cdrage/release-0.7.0

0.7.0 Release

Merge pull request streamlink#910 from cdrage/release-0.6.0

0.6.0 Release

Merge pull request streamlink#762 from cdrage/release-0.5.0

0.5.0 Release