v1.2.0

allow traffic inside security group @kevcube (#145)

boolean flag to enable intra-security group communication.

why

• we create our app infrastructure beginning with the database, then we use the output security group ID that gets created by Postgres as an input in our application, to give it database access
• previously what we've done is create the database, create the app, and add the app security group to the database's inputs, but this makes circular dependencies because our app depends on other outputs of the database