fixed issues with editor with refactored rendertools.py

removed prints for debugging.
updated notebooks to new rendering code --> Tests should pass

flatland/envs/observations.py

@@ -22,12 +22,12 @@ class TreeObsForRailEnv(ObservationBuilder):
     For details about the features in the tree observation see the get() function.
     """
 
-    observation_dim = 9
+
 
     def __init__(self, max_depth, predictor=None):
         super().__init__()
         self.max_depth = max_depth
-
+        self.observation_dim = 9
         # Compute the size of the returned observation vector
         size = 0
         pow4 = 1