Review & decide on a serverless framework

[beechnut]

Background
We want to select a serverless framework so we don't have to change it later during application development.

Criteria include:

• general capabilities and limitations
• how they work with API Gateway
• how they work in different environments

We'll know we're done when...

• We have approved an ADR deciding on a serverless framework that researches Serverless, Claudia.js, SAM, and any other viable candidates.

Tasks

• Draft an ADR with initial research
• Have team members review the ADR, add research, etc.
• Approve the ADR

[beechnut]

Note that this shouldn't be a blocker to completing #347—Claudia.js is two small files and one line of code (npm run update), so can be swapped out easily.