* API design rule support (#1134):
- Change config model
- Change Flask, Starlette, and Django apps for API rule adherence
- Add Flask and Starlette mock clients to test API rule adherence
- Add get_base_url() util function to replace all config['server']['url'] refs
- Ensure that any internal links have URL prefixes if needed
- Add tests and update docs
* Prevent fcntl import error (breaks tests when running locally on Windows)
* Prefer trailing slash in landing page URL when strict_slashes=True (#1134)