Triton Manta allows an account other than the main triton account to be used via RBAC.
Here we expose the SDC_USER / TRITON_USER options to the backend so that a user can be specified.
This PR changes manta from being a legacy remote state client to a new backend type. This also includes creating a simple lock within manta
This PR also unifies the way the triton client is configured (the schema) and also uses the same env vars to set the backend up
It is important to note that if the remote state path does not exist, then the backend will create that path. This means the user doesn't need to fall into a chicken and egg situation of creating the directory in advance before interacting with it
Paul Stack