* geis does not work with channels2 and never will be (it has to be python now)
* pytest
* rewrote cache system
* use username instead of pk for admin user in tests
Uses django channels instead of tornado for the autoupdate. Therefore
tornado is nolonger a dependency of OpenSlides (but channels).
This uses websockets instead of SockJS.
Use the flag insecure in the start command to provide static files serving.
Use a new session backend that has a ForeignKey to User.
