Move the repopulation of the redis cache into a different service

[vidia]

In order for us to better version our API in the future, we will need to run multiple versions of this codebase at the same time. Right now, if we decide to do that, it would query the WashAlert site once per minute per version, which is not good.

I think a better way would be to have a cache like we have, then have a service that ONLY queries WashAlert every minute to populate Redis.

Then the API will request from Redis if it exists. If the key is not in redis (Which should not happen, but we should handle this case) then request WashAlert directly.

Then we can make multiple versions of the PAI, but only ever need one copy of the refresh server. We can consider lumping the statistic logging functions into this as well, which might be the cleanest way for us.