ExtDeprecationWarning on flask >= 0.11

[lixxu]

flask 0.11 will issue a ExtDeprecationWarning for flask.ext.cache format.

C:\python27\lib\site-packages\flask\exthook.py:71: ExtDeprecationWarning: Importing flask.ext.cache is deprecated, use flask_cache instead.

[hitigon]

#139 has fixed this issue. but seems nobody is maintaining this project anymore, last commit is almost two years ago.

[lixxu]

duplicate with #139