horizon.py: convert dict keys and dict values to list.

gstlal-inspiral/python/plots/horizon.py

@@ -182,8 +182,8 @@ class HorizonDistance:
 
 		mint = int(min([min(horizon_history.keys()) for _, horizon_history in self.horizon_history_dict.items()]))
 		for ifo, horizon_history in self.horizon_history_dict.items():
-			GPSTime = numpy.array(horizon_history.keys())
-			horizon_dist = horizon_history.values()
+			GPSTime = numpy.array(list(horizon_history.keys()))
+			horizon_dist = list(horizon_history.values())
 
 			minh, maxh = (float("inf"), 0)
 			maxh = max(maxh, max(horizon_dist))