Update from Go 1.7 to 1.8 (#2110)
Update from Go 1.7 to 1.8 (#2110)

- Increase build speed by as much as 15%
tysonnorris/openwhisk,rabbah/openwhisk,RSulzmann/openwhisk,duynguyen/incubator-openwhisk,style95/openwhisk,prccaraujo/openwhisk,rabbah/openwhisk,xin-cai/openwhisk,cbickel/openwhisk,prccaraujo/openwhisk,markusthoemmes/openwhisk,prccaraujo/openwhisk,domdom82/openwhisk,houshengbo/openwhisk,akrabat/openwhisk,tysonnorris/openwhisk,RSulzmann/openwhisk,rabbah/openwhisk,prccaraujo/openwhisk,houshengbo/openwhisk,sven-lange-last/openwhisk,jasonpet/openwhisk,xin-cai/openwhisk,jasonpet/openwhisk,dubeejw/openwhisk,markusthoemmes/openwhisk,tysonnorris/openwhisk,style95/openwhisk,devbv/incubator-openwhisk,paulcastro/openwhisk,paulcastro/openwhisk,RSulzmann/openwhisk,prccaraujo/openwhisk,tysonnorris/openwhisk,starpit/openwhisk,sven-lange-last/openwhisk,xin-cai/openwhisk,jasonpet/openwhisk,style95/openwhisk,csantanapr/incubator-openwhisk,prccaraujo/openwhisk,domdom82/openwhisk,devbv/incubator-openwhisk,lzbj/openwhisk,domdom82/openwhisk,rabbah/openwhisk,jasonpet/openwhisk,sven-lange-last/openwhisk,dubeejw/openwhisk,sven-lange-last/openwhisk,duynguyen/incubator-openwhisk,starpit/openwhisk,akrabat/openwhisk,houshengbo/openwhisk,paulcastro/openwhisk,style95/openwhisk,rabbah/openwhisk,domdom82/openwhisk,akrabat/openwhisk,cbickel/openwhisk,tysonnorris/openwhisk,CrowdFlower/incubator-openwhisk,duynguyen/incubator-openwhisk,lzbj/openwhisk,rabbah/openwhisk,houshengbo/openwhisk,jeremiaswerner/openwhisk,paulcastro/openwhisk,duynguyen/incubator-openwhisk,csantanapr/incubator-openwhisk,jeremiaswerner/openwhisk,openwhisk/openwhisk,cbickel/openwhisk,dubeejw/openwhisk,cbickel/openwhisk,jeremiaswerner/openwhisk,style95/openwhisk,markusthoemmes/openwhisk,akrabat/openwhisk,akrabat/openwhisk,akrabat/openwhisk,starpit/openwhisk,CrowdFlower/incubator-openwhisk,csantanapr/incubator-openwhisk,jasonpet/openwhisk,duynguyen/incubator-openwhisk,rabbah/openwhisk,starpit/openwhisk,lzbj/openwhisk,lzbj/openwhisk,xin-cai/openwhisk,RSulzmann/openwhisk,openwhisk/openwhisk,starpit/openwhisk,jeremiaswerner/openwhisk,jeremiaswerner/openwhisk,domdom82/openwhisk,tysonnorris/openwhisk,csantanapr/incubator-openwhisk,devbv/incubator-openwhisk,lzbj/openwhisk,jeremiaswerner/openwhisk,jeremiaswerner/openwhisk,CrowdFlower/incubator-openwhisk,cbickel/openwhisk,openwhisk/openwhisk,markusthoemmes/openwhisk,sven-lange-last/openwhisk,RSulzmann/openwhisk,csantanapr/incubator-openwhisk,paulcastro/openwhisk,starpit/openwhisk,paulcastro/openwhisk,devbv/incubator-openwhisk,openwhisk/openwhisk,RSulzmann/openwhisk,cbickel/openwhisk,jasonpet/openwhisk,tysonnorris/openwhisk,cbickel/openwhisk,xin-cai/openwhisk,devbv/incubator-openwhisk,paulcastro/openwhisk,style95/openwhisk,markusthoemmes/openwhisk,houshengbo/openwhisk,jasonpet/openwhisk,markusthoemmes/openwhisk,xin-cai/openwhisk,CrowdFlower/incubator-openwhisk,sven-lange-last/openwhisk,CrowdFlower/incubator-openwhisk,style95/openwhisk,markusthoemmes/openwhisk,csantanapr/incubator-openwhisk,prccaraujo/openwhisk,houshengbo/openwhisk,domdom82/openwhisk,markusthoemmes/openwhisk,dubeejw/openwhisk,CrowdFlower/incubator-openwhisk,dubeejw/openwhisk,lzbj/openwhisk,sven-lange-last/openwhisk,RSulzmann/openwhisk,akrabat/openwhisk,openwhisk/openwhisk,csantanapr/incubator-openwhisk,houshengbo/openwhisk,openwhisk/openwhisk,dubeejw/openwhisk