BROOKLYN-83: fix SensorResourceTest

- On getting a sensor, if no "Accepts" header is given, then we don't 
  control whether json or plain text comes back.
  It is dependent on the method order, which is compiler-specific.
- Therefore delete the test that gave no Accepts and then asserted
  it was json.
BROOKLYN-85: fix FixedListMachineProvisioningLocationTest