setup dev infrastructure for ballotnav backend

[jafow]

Overview

once an mvp version of the app is runnable we will need to deploy it into a cloud environment.

Action Items

• [x] build a terraform config for ALB -> ECS in the existing ballotnav dev vpc
• [x] assert that we can curl api.dev.ballotnav.org/status with a 200 OK
• [ ] terraform code is checked into git
• [] document this in a .md file here