This was already added to triton-go and is now making its way to
the manta backend
```
% acctests backend/remote-state/manta
=== RUN TestBackend_impl
--- PASS: TestBackend_impl (0.00s)
=== RUN TestBackend
--- PASS: TestBackend (27.36s)
=== RUN TestBackendLocked
--- PASS: TestBackendLocked (16.24s)
=== RUN TestRemoteClient_impl
--- PASS: TestRemoteClient_impl (0.00s)
=== RUN TestRemoteClient
--- PASS: TestRemoteClient (3.40s)
=== RUN TestRemoteClientLocks
--- PASS: TestRemoteClientLocks (7.17s)
PASS
ok github.com/hashicorp/terraform/backend/remote-state/manta
```