error handling

[seriousme]

the vote app submits any data you throw at it into the queue.
https://github.com/subfuzion/docker-voting-app-nodejs/blob/master/src/vote/app.js#L32

Only at database level the body of the post operation is verified
https://github.com/subfuzion/docker-voting-app-nodejs/blob/master/src/database/lib/Database.js#L211

validating at the vote app level will ensure that only valid data is submitted to the queue and also simplifies error handling towards the client. It also reduces risk as there is no chance of unknown data of unknown size being queued.

Ideally the interface between voter and vote would be documented in an OpenApi (aka swagger) spec so code can be generated for both client and server which will automatically include validity checks.