Remove deprecation warning from Django 1.8

[Gagaro]

RemovedInDjango19Warning: `request.REQUEST` is deprecated, use `request.GET` or `request.POST` instead.

[Gagaro]

@stephane Could you take a look at this short pull request plz ? Thanks.

[stephane]

Thank you @Gagaro for your patch, it reminds me I didn't push my local changes ;)
So it's fixed now, I just need to push a new release on pypi.