[util] tests for util/debug.py
[util] tests for util/debug.py

avehtari/GPy,ysekky/GPy,esiivola/GPYgradients,dhhjx880713/GPy,SheffieldML/GPy,mikecroucher/GPy,befelix/GPy,avehtari/GPy,esiivola/GPYgradients,avehtari/GPy,avehtari/GPy,mikecroucher/GPy,dhhjx880713/GPy,esiivola/GPYgradients,dhhjx880713/GPy,befelix/GPy,dhhjx880713/GPy,mikecroucher/GPy,befelix/GPy,ysekky/GPy,SheffieldML/GPy,esiivola/GPYgradients,SheffieldML/GPy,befelix/GPy,ysekky/GPy,SheffieldML/GPy,mikecroucher/GPy,ysekky/GPy