add default support for coffeescript (#40)

Author: noman798

lib/loader.js

@@ -82,6 +82,7 @@ module.exports = function (content) {
       loader: 'ts-loader',
       options: { appendTsSuffixTo: [/\.vue$/] }
     }],
+    coffee:['coffee-loader'],
     scss: ['sass-loader'],
     sass: [{
       loader: 'sass-loader',