Merge pull request #285 from davvid/1.x-compat

PR: Import Callable and MutableMapping in py3compat for Python 2 compat

qtpy/py3compat.py

@@ -46,6 +46,7 @@
 if PY2:
     # Python 2
     import __builtin__ as builtins
+    from collections import Callable, MutableMapping
     import ConfigParser as configparser
     try:
         import _winreg as winreg