Reported: Yarxiv ref: 1605.05761doi: 10.1007/JHEP09(2016)037Authors: C. Anastasiou, C. Duhr, F. Dulat, E. Furlan, T. Gehrmann, F. Herzog, A. Lazopoulos, B. MistlbergerNode: UZHSenior Scientist: Gehrmann