fix import issue on no-gpu machine
fix import issue on no-gpu machine

mikecroucher/GPy,dhhjx880713/GPy,PredictiveScienceLab/GPy,gusmaogabriels/GPy,SheffieldML/GPy,mikecroucher/GPy,AlexGrig/GPy,avehtari/GPy,ptonner/GPy,ptonner/GPy,jameshensman/GPy,ptonner/GPy,dhhjx880713/GPy,maaskola/GPy,avehtari/GPy,PredictiveScienceLab/GPy,SheffieldML/GPy,gusmaogabriels/GPy,ysekky/GPy,Dapid/GPy,SheffieldML/GPy,fivejjs/GPy,TianpeiLuke/GPy,befelix/GPy,buntyke/GPy,AlexGrig/GPy,ysekky/GPy,beckdaniel/GPy,TianpeiLuke/GPy,strongh/GPy,esiivola/GPYgradients,AlexGrig/GPy,TianpeiLuke/GPy,Dapid/GPy,beckdaniel/GPy,befelix/GPy,AlexGrig/GPy,fivejjs/GPy,PredictiveScienceLab/GPy,ysekky/GPy,buntyke/GPy,maaskola/GPy,ptonner/GPy,befelix/GPy,gusmaogabriels/GPy,avehtari/GPy,beckdaniel/GPy,buntyke/GPy,beckdaniel/GPy,mikecroucher/GPy,fivejjs/GPy,befelix/GPy,dhhjx880713/GPy,mikecroucher/GPy,ysekky/GPy,maaskola/GPy,strongh/GPy,dhhjx880713/GPy,jameshensman/GPy,Dapid/GPy,esiivola/GPYgradients,buntyke/GPy,Dapid/GPy,esiivola/GPYgradients,strongh/GPy,esiivola/GPYgradients,SheffieldML/GPy,avehtari/GPy,PredictiveScienceLab/GPy,jameshensman/GPy,maaskola/GPy,jameshensman/GPy