CocoaPods安装

CocoaPods安装，如果您此前已安装，请跳过此步骤。
移除现有的Ruby默认源
gem sources --remove https://rubygems.org/
使用新源
gem sources -a https://ruby.taobao.org/
验证新源替换是否成功
gem sources -l
安装CocoaPods
sudo gem install cocoapods
至此为止，整个CocoaPods就已安装成功了。