feat(tests/lean/test_single): show unified diffs with color
feat(tests/lean/test_single): show unified diffs with color

leanprover-community/lean,digama0/lean,johoelzl/lean,digama0/lean,leodemoura/lean,digama0/lean,johoelzl/lean,avigad/lean,leanprover-community/lean,digama0/lean,Kha/lean,fpvandoorn/lean,rlewis1988/lean,leodemoura/lean,leodemoura/lean,rlewis1988/lean,digama0/lean,johoelzl/lean,Kha/lean,dselsam/lean,leanprover-community/lean,leodemoura/lean,fpvandoorn/lean,leanprover/lean,rlewis1988/lean,fpvandoorn/lean,avigad/lean,fpvandoorn/lean,leodemoura/lean,Kha/lean,leanprover/lean,avigad/lean,leodemoura/lean,Kha/lean,Kha/lean,johoelzl/lean,johoelzl/lean,rlewis1988/lean,leanprover-community/lean,digama0/lean,dselsam/lean,dselsam/lean,rlewis1988/lean,leanprover/lean,leanprover-community/lean,fpvandoorn/lean,johoelzl/lean,dselsam/lean,leanprover/lean,dselsam/lean,fpvandoorn/lean,Kha/lean,dselsam/lean,leanprover/lean,avigad/lean,leanprover-community/lean,rlewis1988/lean,avigad/lean,avigad/lean,leanprover/lean