pod install提示：bad interpreter: No such file or directory信息

执行pod install命令后出现了下面提示：

-bash: /usr/local/bin/pod: /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby: bad interpreter: No such file or directory

上述问题是升级了Mac系统导致的，当升级了新的系统后，别忘记更新cocoapods。执行命令为：

 $ sudo gem update --system
 $ sudo gem install cocoapods -n/usr/local/bin