Merge pull request #498 from xing-yang/changelog_5.2.0

Add changelog for v5.2.0

Merge pull request #481 from xing-yang/changelog_5.1.0

Add changelog for v5.1.0

Merge pull request #383 from pohly/changelog-5.0.0

prepare v5.0.0 release

Merge pull request #378 from xing-yang/changelog_4.4

Add changelog for v4.4

Merge pull request #352 from pohly/release-4.3.0

changelog for v4.3.0

Merge pull request #339 from pohly/prow-update-master

master: update release-tools

Merge pull request #328 from pohly/release-4.1.0

release v4.1.0

Merge pull request #306 from msau42/docs

Add v4.0.2 changelog and move all changelogs into a directory

Merge pull request #290 from xing-yang/changelog_4.0.1

Add changelog for 4.0.1

Merge pull request #285 from xing-yang/changelog

Add changelog for v4.0.0