https://github.com/CocoaPods/Specs.git 源找不到版本 3.1.3

It is recommended to refer to the following process before submitting issues：https://github.com/didi/DoraemonKit/issues/745
If you still cannot solve your problem, you can submit your issue according to the following template

Please complete the following informations.
> Android、iOS? OS version? Brand?
ios
> Expected behavior and actual behavior.
> Steps to reproduce the problem.
> More informations such as error messages and stack traces are welcomed.
>

建议提issues之前可以参考一下DoKit社区答疑流程：https://github.com/didi/DoraemonKit/issues/745
假如还是无法解决你的问题，你可以按照以下模板来提交你的issue

请补充如下信息。
> Android 还是 iOS？系统版本是多少？手机品牌是什么？（如有）
> 期望的表现和实际的表现。（如有）
> 问题重现的步骤。（如有）
> 其他的错误信息和堆栈信息如果有也可以一并提供出来。（如有）

https://github.com/CocoaPods/Specs.git 源找不到版本 3.1.3
'https://cdn.cocoapods.org' 可以找到