tasks: CalDAV provider (Nextcloud Tasks/iOS), review reports unknown values; bump stops pointing at release (#139)

Files changed:
- CHANGES.md
- INSTALL.md
- VERSION
- instructions/dev/version-parts.md
- instructions/gtd-weekly-review/SKILL.md
- tools/CONTRACT.md
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/version_cmd.py
- tools/chemenu/review.py
- tools/chemenu/tasks/__init__.py
- tools/chemenu/tasks/caldav.py
- tools/chemenu/tasks/config.py
- tools/chemenu/tests/test_caldav.py
- tools/chemenu/tests/test_doctor.py
- tools/chemenu/tests/test_review.py
- tools/requirements.txt

VERSION

@@ -1 +1 @@
-7.0.0
+7.1.0-beta.2