forward-sdk 0.1.23

Added

• client.access() and forward_sdk.Access: whether an account's roles allow an
  operation, answered the way Forward's enforcer answers it and without making the call.
  access.may("NetworkOperation.TRIGGER_SNAPSHOT_COLLECTION") gives a Decision:
  allowed is True, False, or None when the roles cannot settle it, with a reason and
  the role it rested on; can() returns just allowed. The roles are read once per client,
  and a refusal to read them gives None rather than raising. describe_operation() and operations() list
  each operation's access type, licence facet and lowest network role. The table of
  operations and the roles that hold them is read from Forward's own source (a checkout
  named by FORWARD_SOURCE, or a JSON copy by FORWARD_RBAC_TABLE), because Forward
  serves no endpoint for it. It is not shipped with the SDK; without one every answer is
  None and says so. See what an account may do.

Fixed

• error.denial also reads "No permission for network operation X", which Forward's service code throws instead of the enforcer's "Missing permission".