调试程序的时候，出现：
diff: /../Podfile.lock: No such file or directory
diff: Manifest.lock: No such file or directory
error: The sandbox is not in sync with the Podfile.lock. Run ‘pod install’ or update your CocoaPods installation.
解决方式:
关闭当前的工作空间，删除掉文件夹中的workspace，然后重新pod install，install完成之后，通过workspace打开工作空间，clean+build即可，如下所示
rm -rf MyProject.xcworkspace
sudo gem install cocoapods
pod setup
pod install
