Each PR must conform to [Developer's Guide](http://gettaurus.org/docs/DeveloperGuide/#Rules-for-Contributing).

Quick checklist:
- [ ] Description of PR explains the context of change
- [ ] Unit tests cover the change, no broken tests
- [ ] No static analysis warnings (Codacy etc.)
- [ ] Documentation update
- [ ] Changes file inside `site/dat/docs/changes` directory, one-line note of change inside

Each PR must conform to [Developer's Guide](http://gettaurus.org/docs/DeveloperGuide/#Rules-for-Contributing).

Quick checklist:
- [ ] Description of PR explains the context of change
- [ ] Unit tests cover the change, no broken tests
- [ ] No static analysis warnings (Codacy etc.)
- [ ] Documentation update ('available in the unstable snapshot' warning if necessary)
- [ ] Changes file inside `site/dat/docs/changes` directory, one-line note of change inside

Add 'available in unstable snapshot' warning reminder to the quick cheklist
Add 'available in unstable snapshot' warning reminder to the quick cheklist
