This demo only works with 5.6.X or lower, it's not working with 5.7.x as of yet.
This repositiory holds the current (2.2.0 at the time of writing) version of Slim and basic libraries for booting & working with Concrete5 in the Slim micro framework.
It also provides a fully functioning demo of Slim booting & calling Concrete5, it also holds a version of the basic HTTP authentication library modified to use Concrete5 as an authentication database.