[Update Curriculum for WallJump] Updating the curriculum for WallJump (#774)

python/curricula/wall.json

 {
-    "measure" : "reward",
-    "thresholds" : [0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5],
+    "measure" : "progress",
+    "thresholds" : [0.1, 0.3, 0.5],
-        "min_wall_height" : [0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5],
-        "max_wall_height" : [1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0]
+        "big_wall_min_height" : [0.0, 4.0, 6.0, 8.0],
+        "big_wall_max_height" : [4.0, 7.0, 8.0, 8.0],
+        "small_wall_height" : [1.5, 2.0, 2.5, 4.0]
     }
 }