'create_date' is evidently a typo

I added an alias for backwards compatibility, is that needed?

trello/card.py

@@ -336,7 +336,7 @@ def get_stats_by_list(self, tz, lists, list_cmp=None, done_list=None, time_unit=
             seconds_to_time_unit = lambda time: time / 3660.0
 
         # Creation datetime of the card
-        creation_datetime = self.create_date
+        creation_datetime = self.created_date
 
         #  Time in seconds stores the seconds that our card lives in a column
         stats_by_list = {list_.id: {"time":0, "forward_moves":0, "backward_moves":0} for list_ in lists}
@@ -402,7 +402,7 @@ def latestCardMove_date(self):
         return dateparser.parse(date_str)
 
     @property
-    def create_date(self):
+    def created_date(self):
         """Will return the creation date of the card.
 
         WARNING: if the card was create via convertion of a checklist item
@@ -413,6 +413,9 @@ def create_date(self):
         date_str = self.actions[0]['date']
         return dateparser.parse(date_str)
 
+    # backwards compatibility alias; TODO: deprecation message
+    create_date = created_date
+
     @property
     def card_created_date(self):
         """Will return the creation date of the card.