私有Pod的一些问题与处理办法

CocoaPods 组件化实践 - 私有Pod
http://www.jianshu.com/p/475d6b6d5600

使用Cocoapods创建私有podspec
http://www.cocoachina.com/ios/20150228/11206.html

无法 pod spec lint 的问题解决办法
http://www.cnblogs.com/xzjxylophone/p/4956469.html

报错：
[!] The validator for Swift projects uses Swift 3.0 by default, if you are using a different version of swift you can use a `.swift-version` file to set the version for your Pod. For example to use Swift 2.3, run: 
    `echo "2.3" > .swift-version`.
You can use the `--no-clean` option to inspect any issue.

解决办法：
echo "2.3" > .swift-version

报错：
[Cocoapods: Unable to find a specification for [PrivateSpec] depended upon by [PrivateClientSpec]](https://stackoverflow.com/questions/27303475/cocoapods-unable-to-find-a-specification-for-privatespec-depended-upon-by-pr)

解决办法：
https://stackoverflow.com/questions/27303475/cocoapods-unable-to-find-a-specification-for-privatespec-depended-upon-by-pr