[chore] Release 6.7.0 (#867)

[chore] Release 6.6.0 Take 2 (#830)

[chore] Release 6.5.0 (#779)

[chore] Release 6.4.0 Take 3 (#763)

[chore] Release 6.3.0 (#742)

[chore] Release 6.2.0 (#708)

- Release 6.2.0

[chore] Release 6.1.0 (#672)

- Release 6.1.0

[chore] Release 6.0.1 (#655)

- Release 6.0.1

[chore] Release 6.0.0 (#649)

* [chore] Release 6.0.0

- Major version bump to drop support for Python 3.6
- Added `app_check.verify_token()` API

[chore] Release 5.4.0 (#647)

* [chore] Release 5.4.0

Release v5.4.0
Deprecated Python 3.6 (reached EoL)