Add git bisector scripts

This contains bisect_git.py and switch_git.py

Change-Id: I7cf5eb895ebd9ce803b745c51498b4b151ddc76b
diff --git a/switch_git_test.py b/switch_git_test.py
new file mode 100644
index 0000000..78ab171
--- /dev/null
+++ b/switch_git_test.py
@@ -0,0 +1,29 @@
+# Copyright 2017 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""Test switch_git script."""
+
+from __future__ import print_function
+import unittest
+
+import mock
+
+import switch_git
+
+
+@mock.patch('bisect_kit.common.config_logging', mock.Mock())
+class TestSwitchGit(unittest.TestCase):
+  """Test switch_git.py."""
+
+  def test_main(self):
+    with mock.patch('bisect_kit.cli.argtype_dir_path', lambda x: x):
+      with mock.patch('bisect_kit.git_util.checkout_version') as mock_func:
+        git_repo = '/path/to/git/repo'
+        rev = '123456789'
+        switch_git.main(['--git_repo', git_repo, rev])
+
+        mock_func.assert_called_with(git_repo, rev)
+
+
+if __name__ == '__main__':
+  unittest.main()