caching: invalidate Repository cache of README and RSS based on latest revision hash in its .changeset_cache Avoid using the the more heavy and complex CacheInvalidation. Note that raw_id only is passed to the getter function as cache key, in order to make sure new data is retrieved whenever the repo changes.

pytest >= 4.6.6, < 4.7
pytest-sugar >= 0.9.2, < 0.10
pytest-benchmark >= 3.2.2, < 3.3
pytest-localserver >= 0.5.0, < 0.6
mock >= 3.0.0, < 3.1
Sphinx >= 1.8.0, < 1.9
WebTest >= 2.0.3, < 2.1
isort == 4.3.21