Arnav Singh

readOnly operations fail against registries that require basic auth

1

For private registries, one must be able to provide basic auth creds, via `NOTARY_AUTH` env var or interactively. However, the code assumes that all `readOnly` operations [can be anonymous,](https://github.com/theupdateframework/notary/blob/5b8946ccb2fe7bd7b5a1c893ceb3191d09bf2fad/cmd/notary/tuf.go#L952) which...