Update schema and logic to persist balance

[matt-goldman]

Consider snapshotting achievement value

[tkapa]

Hey @matt-goldman,

We are looking at this now. Is this still required?

My interpretation of this is that we currently don't take a "ledger table" approach to points balance. Therefore if an achievement's value were to change later on it would affect the user's points balance.

1. If this is the case, I don't believe that we do this currently. Please expand on the PBI above

[matt-goldman-ssw]

Hey @tkapa

Yes that's correct. We would probably need event sourcing for this.