gem sources -l
gem sources --remove https://rubygems.com/
gem source --add https://gems.ruby-china.com
sudo gem install cocoapods
pod setup
安装问题
RPC failed; curl 56 LibreSSL SSL_read: SSL_ERROR_SYSCALL, errno 54
手动下载https://github.com/CocoaPods/Specs.git ，放入~/.cocoapods/repos目录下，命名 master
或者终端执行
cd ~/.cocoapods/repos/master
git clone https://github.com/CocoaPods/Specs.git
常用更新
pod install --verbose --no-repo-update
pod update --verbose --no-repo-update
