CI/CD in a Serverless context

1. Why not just roll your own CI server with serverless?

 * Looks like there’s a github project repo that does that: https://github.com/lambci/lambci
 * Build vs buy discussion

2. How can we run our serverless app locally pre merge (given TBD)

 * `sam local invoke` perhaps?
 * Create a sub account per dev to isolate them and allow spin up of whatever services