Import with flask_cache

[vindarel]

fixes #156

Hi, hope that's ok !

[vindarel]

Looks like the CI is broken:

pip install . --use-mirrors
=> no such option: --use-mirrors

on a previous build:

--use-mirrors has been deprecated and will be removed in the future. Explicit uses of --index-url and/or --extra-index-url is suggested.

[vindarel]

argh

• https://github.com/thadeusb/flask-cache/issues/142
• new project: https://github.com/sh4nks/flask-caching