Change the order of base classes for cursor.

With this change it is possible to monkey-patch execute method
to SimpleCursorBase and get interesting logs of everything
that goes through.

Author: zbynekwinkler

postgres/cursors.py

@@ -152,15 +152,15 @@ def all(self, sql, parameters=None):
         return recs
 
 
-class SimpleTupleCursor(TupleCursor, SimpleCursorBase):
+class SimpleTupleCursor(SimpleCursorBase, TupleCursor):
     """A `simple cursor`_ that returns tuples.
     """
 
-class SimpleNamedTupleCursor(NamedTupleCursor, SimpleCursorBase):
+class SimpleNamedTupleCursor(SimpleCursorBase, NamedTupleCursor):
     """A `simple cursor`_ that returns namedtuples.
     """
 
-class SimpleDictCursor(RealDictCursor, SimpleCursorBase):
+class SimpleDictCursor(SimpleCursorBase, RealDictCursor):
     """A `simple cursor`_ that returns dicts.
     """