Re-enabled 'raise' test case.

tests/test_parser.py

@@ -24,5 +24,5 @@ class TestParser(unittest.TestCase):
     def test_line(self):
         self.assertEqual(line(Parser, '4a'), '4 * a')
 
-    #def test_raise(self):
-    #    ParserWrapper(Parser).run(['raise'])
+    def test_raise(self):
+        ParserWrapper(Parser).run(['raise'])