Wrap async with test in async def

Bare `async with` only works in 3.7 and higher

ropetest/refactor/extracttest.py

@@ -2960,31 +2960,32 @@ async def afunc():
                 async with open("test") as file1:
                     print(file1)
         """)
-        start, end = self._convert_line_range_to_offset(code, 3, 3)
+        start, end = self._convert_line_range_to_offset(code, 2, 3)
         refactored = self.do_extract_method(code, start, end, 'extracted', global_=True)
         expected = dedent("""\
             async def afunc():
-                async with open("test") as file1:
-                    extracted(file1)
+                extracted()
 
-            def extracted(file1):
-                print(file1)
+            def extracted():
+                async with open("test") as file1:
+                    print(file1)
         """)
         self.assertEqual(expected, refactored)
 
     def test_extract_method_async_with_double_with_as(self):
         code = dedent("""\
-            async with open("test") as file1, open("test") as file2:
-                print(file1, file2)
+            async def afunc():
+                async with open("test") as file1, open("test") as file2:
+                    print(file1, file2)
         """)
-        start, end = self._convert_line_range_to_offset(code, 2, 3)
+        start, end = self._convert_line_range_to_offset(code, 3, 3)
         refactored = self.do_extract_method(code, start, end, 'extracted', global_=True)
         expected = dedent("""\
+            async def afunc():
+                async with open("test") as file1, open("test") as file2:
+                    extracted(file1, file2)
 
             def extracted(file1, file2):
                 print(file1, file2)
-
-            async with open("test") as file1, open("test") as file2:
-                extracted(file1, file2)
         """)
         self.assertEqual(expected, refactored)