CI: install xsltproc in before_script, drop apt-get from after_script libeigen/eigen!2516 Co-authored-by: Rasmus Munk Larsen <rmlarsen@gmail.com>
Eigen is a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms.
For more information go to http://eigen.tuxfamily.org/ or https://libeigen.gitlab.io.
For pull request, bug reports, and feature requests, go to https://gitlab.com/libeigen/eigen.