打开很久以前的项目报错，很多.a文件都找不到，想着更新下第三方框架的包，
pod install
错误信息：
Re-creating CocoaPods due to major version update.
Analyzing dependencies
[!] The dependency `ELCImagePickerController (~> 0.2.0)` is not used in any concrete target.
The dependency `MBProgressHUD (~> 0.9.2)` is not used in any concrete target.
The dependency `MJExtension (~> 3.0.10)` is not used in any concrete target.
The dependency `MJRefresh (~> 3.1.0)` is not used in any concrete target.
The dependency `AFNetworking (~> 3.0)` is not used in any concrete target.
The dependency `SDWebImage (~> 3.7)` is not used in any concrete target.
The dependency `UMengAnalytics-NO-IDFA (~> 3.6.0)` is not used in any concrete target.
解决方案：
1，删除Podfile文件
2，打开Terminal进入项目路径
3，pod init
4，编辑Podfile文件
5，pod install
