Fixed python class filename

Author: Your Name

Example2/discrete_tf.py renamed to Example2/discretetf.py

@@ -35,10 +35,12 @@ def __init__(self, model="discrete_tf"):
     def initialize(self):
         """Initialize the Model."""
         self.__initialize()
+        self.step_num = -1
 
     def step(self):
         """Step through the model Model."""
-        self.step_num = self.__step()
+        self.__step()
+        self.step_num += 1
 
     def terminate(self):
         """Terminate the model Model."""