Feature Request > ability to use github unique ID for github_membership

Currently we can only provide a username to in the `github_membership` and `github_user` data sources. We're interested in using the unique identifier found at `https://api.github.com/users/{USERNAME}` in the `"id"` field. This is because username can be changed by the user, which causes our terraform scripts for github memberships to be out of date. The `id` cannot be changed and is globally unique, which makes it a much better candidate.

Instead of providing the username to the `/users` endpoint, you can get the same information by providing the `id` to the `/user` endpoint (e.g. `https://api.github.com/user/{id}`).