Feature Request: Enforce API Authorisers

If you are developing in a team, it can be difficult to ensure that the correct Authoriser is always used for API endpoints. A useful feature would be something in the configuration that allows you enforce authorisers so that even if the developer forgets to add it, during the deploy process Chalice will add the authoriser. This would also save duplicitous authoriser declaration statements throughout the code

Start by tracing Chalice's configuration and deployment process for API endpoints and reviewing existing authoriser documentation. Clarify whether configuration should override or fill missing declarations, then define acceptance coverage for both explicitly authorised and unannotated endpoints.

Written by the indexing model from the issue text.