Support QUnit 1.15.0 and 1.16.0

Support QUnit 1.15.0 and 1.16.0

TODO
----------
- [x] Bump to pre version
- [x] Add 1.15.0 and 1.16.0 to compatibility suite
- [x] Maint compatibility suite
- [x] Drop support for too old before-1.0.0 versions
- [x] Update README