OS X10.11升级安装Cocoapods出现-bash: pod: command not found

升级10.11后，运行pod命令出现：

-bash: pod: command not found

然后运行一下以下命令
sudo gem install -n /usr/local/bin cocoapods

又出现了一个新的问题：
Unable to resolve dependencies: cocoapods requires cocoapods-core (= 1.2.1), cocoapods-downloader (< 2.0, >= 1.1.3), cocoapods-trunk (< 2.0, >= 1.2.0), molinillo (~> 0.5.7), xcodeproj (< 2.0, >= 1.4.4), colored2 (~> 3.1), ruby-macho (~> 1.1)
解决方法：
sudo gem update --system这时在运行一下
sudo gem install -n /usr/local/bin cocoapods

就能看到需要的结果了
可参考如下博文：

http://www.jianshu.com/p/f79cd5256531

http://blog.csdn.net/NSNirvana/article/details/46873071