安装Cocoapods

1:更新gem

sudo gem update --system

2:安装Cocoapods

sudo gem install cocoapods

注意这一步可能出错：

ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted - /usr/bin/fuzzy_match

这时候可以用如下命令安装：

sudo gem install -n /usr/local/bin cocoapods

指定安装版本

sudo gem install -n /usr/local/bin cocoapods -v 1.2.1

3:配置Cocoapods

pod setup