Auto-generate sample repos.

This repo references the following sample repos as examples of our approach:

1. [infrastratructure-live](https://github.com/gruntwork-io/infrastructure-live-acme)
1. [infrastratructure-modules](https://github.com/gruntwork-io/infrastructure-modules-acme)
1. [sample-app](https://github.com/gruntwork-io/sample-app-acme)

But these repos are not currently auto-generated and will inevitable grow stale. Per @brikis98, this Issue proposes we keep these repos up to date automatically. We could do that by configure the CircleCI build for usage-patterns to:

1. Generate the code into these repos
1. Run some tests against this code
1. Commit the code if the tests pass