Storing error values to atomic.Value may fail if they have different
dynamic types. Wrap error value in a consistent struct type to avoid
panics.
Make sure we return a nil error on success
The provisioner collected all inline commands into a single script which meant
only the exit code of the last command was actually checked for an error.
The reason why the shebang is removed from these tests, is because the
shebang is only needed for SSH/Linux connections. So in the new setup
the shebang line is added in the SSH communicator instead of in the
resource provisioner itself…
James Bardin