add license to file

Author: wangjoshuah

OptimizelySDKDatafileManager/OptimizelySDKDatafileManagerTests/OPTLYDatafileManagerTest.m

@@ -1,10 +1,18 @@
-//
-//  OPTLYDatafileManagerTest.m
-//  OptimizelySDKDatafileManager
-//
-//  Created by Josh Wang on 11/14/16.
-//  Copyright © 2016 Optimizely. All rights reserved.
-//
+/****************************************************************************
+ * Copyright 2016, Optimizely, Inc. and contributors                        *
+ *                                                                          *
+ * 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.                                           *
+ ***************************************************************************/
 
 #import <XCTest/XCTest.h>
 #import "OPTLYTestHelper.h"