fix: matplotlib 2.0 mlba -> cbook:
fix: matplotlib 2.0 mlba -> cbook:

esiivola/GPYgradients,SheffieldML/GPy,esiivola/GPYgradients,SheffieldML/GPy,esiivola/GPYgradients,SheffieldML/GPy,esiivola/GPYgradients,SheffieldML/GPy