Apply typing to all of pre-commit-hooks
diff --git a/pre_commit_hooks/forbid_new_submodules.py b/pre_commit_hooks/forbid_new_submodules.py
index c9464cf..bdbd6f7 100644
--- a/pre_commit_hooks/forbid_new_submodules.py
+++ b/pre_commit_hooks/forbid_new_submodules.py
@@ -2,10 +2,13 @@
from __future__ import print_function
from __future__ import unicode_literals
+from typing import Optional
+from typing import Sequence
+
from pre_commit_hooks.util import cmd_output
-def main(argv=None):
+def main(argv=None): # type: (Optional[Sequence[str]]) -> int
# `argv` is ignored, pre-commit will send us a list of files that we
# don't care about
added_diff = cmd_output(
