Fix internal linting setup and add missing headers (#1741)

packages/react-scripts/bin/react-scripts.js

@@ -1,4 +1,15 @@
 #!/usr/bin/env node
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+'use strict';
+
 var spawn = require('cross-spawn');
 var script = process.argv[2];
 var args = process.argv.slice(3);