test(lean/scanner): add more tests for improving coverage
test(lean/scanner): add more tests for improving coverage

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

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