Add a run_eslint wrapper script

common/eslint/bin/run_tests

+#!/usr/bin/env python
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import sys
+
+
+_CATAPULT_PATH = os.path.abspath(
+    os.path.join(os.path.dirname(__file__),
+    os.path.pardir, os.path.pardir, os.path.pardir))
+
+
+_ESLINT_PATH = os.path.abspath(
+    os.path.join(os.path.dirname(__file__), os.path.pardir))
+
+
+def _RunTestsOrDie(top_level_dir):
+  exit_code = run_with_typ.Run(top_level_dir, path=[_ESLINT_PATH])
+  if exit_code:
+    sys.exit(exit_code)
+
+
+def _AddToPathIfNeeded(path):
+  if path not in sys.path:
+    sys.path.insert(0, path)
+
+
+if __name__ == '__main__':
+  _AddToPathIfNeeded(_CATAPULT_PATH)
+
+  from catapult_build import run_with_typ
+
+  _RunTestsOrDie(os.path.join(_ESLINT_PATH, 'eslint'))