BUG: Fix missing warning on py37.

Check LOAD_METHOD in addition to LOAD_ATTR AND STORE_ATTR.

Author: Scott Sanderson

interface/default.py

@@ -81,7 +81,7 @@ def accessed_attributes_of_local(f, local_name):
         # another name.
         for first, second in sliding_window(dis.get_instructions(f), 2):
             if first.opname == 'LOAD_FAST' and first.argval == local_name:
-                if second.opname in ('LOAD_ATTR', 'STORE_ATTR'):
+                if second.opname in ('LOAD_ATTR', 'LOAD_METHOD', 'STORE_ATTR'):
                     used.add(second.argval)
         return used