Merge pull request github#742 from github/release-3.1.0

Bump version: 3.1.0

Merge pull request github#724 from github/release-3.1.0.rc1

Bump version: 3.1.0.rc1

Merge pull request github#712 from github/release-3.0.0

Bump version: 3.0.0

update changelog

Merge pull request github#644 from github/release-2.22.0

Bump version: 2.22.0

Merge pull request github#616 from github/release-2.21.0

Bump version: 2.21.0

Merge pull request github#585 from github/release-2.19.5

Bump version: 2.19.5

Merge pull request github#582 from github/release-2.20.2

Bump version: 2.20.2

Merge pull request github#579 from github/release-2.20.1

Bump version: 2.20.1

Merge pull request github#569 from github/release-2.19.4

Bump version: 2.19.4