Merge pull request #64 from DEIS-Tools/59-python-inconsistent-return-…

…values-for-update_state

#59 Always return state, or raise exception

py_driver/driver.py

@@ -231,8 +231,8 @@ def update_state(self, tube=None, quick=False, initial=False):
             state["Tube1_sonar_dist_mm"] = round(ClaireState.convert_distance_to_level(state["Tube1_sonar_dist_mm"]), 1)
             state["Tube2_sonar_dist_mm"] = round(ClaireState.convert_distance_to_level(state["Tube2_sonar_dist_mm"]), 1)
             self.state = ClaireState(state)
-            return True
-        return False
+            return self.state
+        raise SensorError(f"Failed to retrieve new state, got {state}.")
 
     def _underflow_check(self):
         TAG = "UNDERFLOW_CHECK"