pod update时报错CocoaPods was not able to update the `cocoapods` repo

更新三方库执行pod update时报错[!] CocoaPods was not able to update the cocoapods repo. If this is an unexpected issue and persists you can inspect it running pod repo update --verbose
因为在网上没有搜到报这个错的解决方案，自己解决了就打算发出来权当记录了。
解决办法：
执行：pod repo list

看到有两个repo
cocoapods

• Type: git (unknown)
• URL: https://github.com/CocoaPods/Specs.git
• Path: /Users/amarantine/.cocoapods/repos/cocoapods

master

• Type: git (master)
• URL: https://github.com/CocoaPods/Specs.git
• Path: /Users/amarantine/.cocoapods/repos/master

执行：pod repo remove cocoapods 把不用的repo删除

删除成功后在执行：pod update 就好了