Update package.json.
Update package.json.

Use `license` and remove README.md from the files to install since it's added automatically.

simohaitham/grunt-uncss,tazminweb/grunt-uncss,kingsj/grunt-uncss,simohaitham/grunt-uncss,zabefloyd/grunt-uncss,addyosmani/grunt-uncss,sparanoid/grunt-uncss-inline,zabefloyd/grunt-uncss,kingsj/grunt-uncss,tazminweb/grunt-uncss,addyosmani/grunt-uncss,sparanoid/grunt-uncss-inline