Updated README.md for recent Py3 work
Updated README.md for recent Py3 work

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