chore(util): remove dead file
chore(util): remove dead file

Signed-off-by: Leonardo de Moura <7610bae85f2b530654cc716772f1fe653373e892@microsoft.com>

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