Fix outdated reference to old license

Author: leebyron

src/utilities/__tests__/valueFromASTUntyped-test.js

@@ -1,10 +1,9 @@
 /**
- *  Copyright (c) 2017, Facebook, Inc.
- *  All rights reserved.
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
  *
- *  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.
  */
 
 import { describe, it } from 'mocha';

src/utilities/valueFromASTUntyped.js

@@ -1,11 +1,10 @@
-/* @flow strict */
 /**
- *  Copyright (c) 2017, Facebook, Inc.
- *  All rights reserved.
+ * Copyright (c) 2015-present, Facebook, Inc.
  *
- *  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.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
  */
 
 import keyValMap from '../jsutils/keyValMap';