chore(travis): add build config for 'stable' tests
chore(travis): add build config for 'stable' tests

erickt/hyper,mneumann/hyper,hyperium/hyper,reem/hyper,bheesham/hyper,peterhj/hyper,hannobraun/hyper,mre/hyper,hyperium/hyper,rschulman/hyper,nickgonzales/hyper,hyperium/hyper,Twey/hyper,tempbottle/hyper,softprops/hyper,manuel-woelker/hyper,yazaddaruvala/hyper,hannobraun/hyper,Keats/hyper,ianks/hyper,giftcards/hyper,youprofit/hyper,fuchsnj/hyper,golddranks/hyper,markuskobler/hyper,nickgonzales/hyper,jmmaranan/hyper,hannobraun/hyper,fhahn/hyper,bonifaido/hyper,lame-nickname/hyper,mitsuhiko/hyper,tshepang/hyper,Twey/hyper,tshepang/hyper,nickgonzales/hyper,nstoddard/hyper,golddranks/hyper,achanda/hyper,yangxingpping/hyper,mfeckie/hyper,markuskobler/hyper,pyfisch/hyper,tshepang/hyper,golddranks/hyper,steveklabnik/hyper,yazaddaruvala/hyper,Keats/hyper,TimNN/hyper,sfackler/hyper,Keats/hyper,fengsp/hyper,Twey/hyper,nstoddard/hyper,markuskobler/hyper,clatour/hyper