Cron Endpoint

[qwacko]

Make a cron endpoint with the following functionality:

• Address / key (i.e /cron/xxx) can be configured through environemnt variables to give some protection against hitting the endpoint.
• Make it so that the function can only execute once a minute but using the key/value store (and possibly also a variable).
• Make sure that if minutes are missed, that it runs the correct number of times.
• Make the docker file so that it runs a function to call this endpoint.
• With the fuctionality that allows for the funtion to be only called once a minute, and to make sure it is called every minute then this functionality should be able to replicate cron.

The benefits of this are that it allows for the whole service to be hosted in the cloud (Postgres service for data, S3 for storage and cron endpoint for recurring jobs). Although there may still be challenges with long-running import scripts ecceeding edge runtime limits so that may need to be fixed. Also this means that cron functionality works automatically on docker container start (currently a page needs to be called to have the cron function start up).