The handling of remote variables was completely disabled for push.
We still need to fetch variables from atlas for push, because if the
variable is only set remotely the Input walk will still prompt the user
for a value. We add the missing remote variables to the context
to disable input.
We now only handle remote variables as atlas.TFVar and explicitly pass
around that type rather than an `interface{}`.
Shorten the text fixture slightly to make the output a little more
readable on failures.