Fix minor typo in comment (#172)

Author: trptcolin

python2/koans/about_comprehension.py

@@ -46,7 +46,7 @@ def test_double_list_comprehension(self):
     def test_creating_a_set_with_set_comprehension(self):
         comprehension = { x for x in 'aabbbcccc'}
 
-        self.assertEqual(__, comprehension)  # rememeber that set members are unique
+        self.assertEqual(__, comprehension)  # remember that set members are unique
 
     def test_creating_a_dictionary_with_dictionary_comprehension(self):
         dict_of_weapons = {'first': 'fear', 'second': 'surprise',