Update .travis.osx.yml
Update .travis.osx.yml

disable tcmalloc for OSX
dselsam/lean,leodemoura/lean,UlrikBuchholtz/lean,fpvandoorn/lean,levnach/lean,UlrikBuchholtz/lean,digama0/lean,digama0/lean,eigengrau/lean,fgdorais/lean,leanprover-community/lean,Kha/lean,soonhokong/lean,codyroux/lean0.1,digama0/lean,leanprover/lean,avigad/lean,codyroux/lean0.1,levnach/lean,leodemoura/lean,dselsam/lean,javra/lean,rlewis1988/lean,sp3ctum/lean,codyroux/lean0.1,soonhokong/travis_test,fgdorais/lean,fpvandoorn/lean2,soonhokong/lean,fpvandoorn/lean,digama0/lean,avigad/lean,leanprover/lean,htzh/lean,sp3ctum/lean,eigengrau/lean,c-cube/lean,digama0/lean,johoelzl/lean,eigengrau/lean,javra/lean,fpvandoorn/lean2,fgdorais/lean,avigad/lean,fpvandoorn/lean2,soonhokong/lean-windows,soonhokong/travis_test,sp3ctum/lean,UlrikBuchholtz/lean,soonhokong/lean,leodemoura/lean,avigad/lean,johoelzl/lean,javra/lean,fpvandoorn/lean,soonhokong/travis_test,rlewis1988/lean,johoelzl/lean,fgdorais/lean,htzh/lean,leodemoura/lean,leanprover-community/lean,leanprover/lean,soonhokong/lean-osx,fgdorais/lean,eigengrau/lean,soonhokong/lean-osx,leanprover-community/lean,eigengrau/lean,fpvandoorn/lean,soonhokong/travis_test,soonhokong/lean,Kha/lean,leodemoura/lean,dselsam/lean,dselsam/lean,htzh/lean,johoelzl/lean,Kha/lean,javra/lean,rlewis1988/lean,fpvandoorn/lean2,soonhokong/lean-osx,c-cube/lean,soonhokong/lean-windows,htzh/lean,levnach/lean,fpvandoorn/lean,javra/lean,johoelzl/lean,rlewis1988/lean,Kha/lean,Kha/lean,UlrikBuchholtz/lean,c-cube/lean,leanprover/lean,fpvandoorn/lean2,Kha/lean,johoelzl/lean,dselsam/lean,leanprover/lean,fpvandoorn/lean,soonhokong/lean-windows,leanprover-community/lean,htzh/lean,soonhokong/lean-windows,avigad/lean,codyroux/lean0.1,rlewis1988/lean,leanprover/lean,sp3ctum/lean,dselsam/lean,c-cube/lean,leanprover-community/lean,rlewis1988/lean,soonhokong/lean-osx,soonhokong/lean-windows,soonhokong/lean-osx,soonhokong/lean,avigad/lean,UlrikBuchholtz/lean,sp3ctum/lean,fgdorais/lean,levnach/lean,levnach/lean,leodemoura/lean,c-cube/lean,leanprover-community/lean,digama0/lean