Change references to ${var} from $var in scripts

[daphnegold]

Ticket

Resolves #661

Changes

• New convention applied: update $var to ${var} everywhere in template-bin-only and bin
• Our convention seems to be to add quotes around variables, so the places I noticed those were missing, I added them for safety and consistency

Testing

Platform Test PR Platform Test Deploy

[daphnegold]

Looks great! Thanks so much for tackling this. Much much appreciated.

Can you run just a couple of more tests? In the platform-test repo, in your branch, can you test out the following commands:

1. make infra-set-up-current-account (check to see that it succeeded and no files changed)

2. make infra-update-app-database-roles APP_NAME=app ENVIRONMENT=dev

3. make infra-check-app-database-roles APP_NAME=app ENVIRONMENT=dev

2. and 3. already have screenshots in the platform-test PR. I ran account setup iirc, I'll add screenshot for that when I'm back at my computer.