Investigate options for caching

[jrobchin]

There should be a tool that makes caching easier.

Check out:

• https://www.npmjs.com/package/express-redis-cache
• https://itnext.io/learn-to-cache-your-nodejs-application-with-redis-in-6-minutes-745a574a9739
• https://codeforgeek.com/caching-a-mongodb-database-with-redis/