Support repository renaming

[brettcurtis]

Currently, several actions need to be taken to rename a repository, primarily driven by the decision to use the repository name as the key in the code. An update of the repository name in the prod.tfvars results in the following required state move and a repository name change in the UI.

terraform state mv 'github_repository.this["gke-info-go"]' 'github_repository.this["istio-test"]'

After this, we still have many force destruction changes due to the repository name change.