Fix curriculum smoothing, and use reward for push curriculum

python/curricula/push.json

 {
-    "measure" : "progress",
-    "thresholds" : [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9],
-    "min_lesson_length" : 1,
-    "signal_smoothing" : false, 
+    "measure" : "reward",
+    "thresholds" : [0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65],
+    "min_lesson_length" : 3,
+    "signal_smoothing" : true, 
     "parameters" : 
     {
         "object_size" : [2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1]

python/unityagents/curriculum.py

         if self.data is None or progress is None:
             return {}
         if self.data["signal_smoothing"]:
-            progress = self.smoothing_value * 0.9 + 0.1 * progress
+            progress = self.smoothing_value * 0.1 + 0.9 * progress
             self.smoothing_value = progress
         self.lesson_length += 1
         if self.lesson_number < self.max_lesson_number: