fix test name typo (#478)

Author: DahlitzFlorian

pyflakes/test/test_type_annotations.py

@@ -332,7 +332,7 @@ def f(a, b):
             return a + b
         ''')
 
-    def test_typeCommentsAdditionalComemnt(self):
+    def test_typeCommentsAdditionalComment(self):
         self.flakes("""
         from mod import F