mac 安装 gulp-sass 的坑

Something Wrong with install gulp-sass

I catch error with **npm install gulp-sass **on my mac OSX EI Capitan version 10.11.1
Then I find the way to solute this problem on stackoverflow.

1. sudo xcode-select — switch /Applications/Xcode.app
2. npm install iconv
3. npm **install gulp-sass **

Finally, I am successful!