fix tests that failed around midnight (kimai#735)

release 0.8.1 (kimai#595)

fix sql for only_full_group_by (kimai#581)

prepare release 0.7 (kimai#514)

prepare release 0.6.1 (kimai#433)

prepare release 0.6 (kimai#412)

prepare release 0.5 (kimai#326)

prepare release 0.4 (kimai#292)

prepare release 0.3 (kimai#231)

prepare v0.2 release kimai#177 (kimai#178)

* added CHANGELOG.md and support for github-changelog-generator