Add update-deps for updating vendor dir (knative#353)

hack/update-deps.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+# Copyright 2018 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+source $(dirname $0)/../scripts/library.sh
+
+cd ${REPO_ROOT_DIR}
+
+# Ensure we have everything we need under vendor/
+dep ensure
+
+rm -rf $(find vendor/ -name 'OWNERS')
+rm -rf $(find vendor/ -name '*_test.go')