Add gulp-autoprefixer

Fixes #16

gulpfile.js

@@ -22,6 +22,9 @@ app.css = function (paths, filename) {
         .pipe(plugins.sourcemaps.init())
         .pipe(plugins.sassGlob())
         .pipe(plugins.sass())
+        .pipe(plugins.autoprefixer({
+            browsers: ['last 2 versions']
+        }))
         .pipe(plugins.concat(filename))
         .pipe(config.production ? plugins.cleanCss() : plugins.util.noop())
         .pipe(plugins.if(config.sourceMaps, plugins.sourcemaps.write('.')))

package.json

@@ -4,6 +4,7 @@
     "coffee-script": "^1.10.0",
     "del": "^2.2.0",
     "gulp": "^3.9.0",
+    "gulp-autoprefixer": "^3.1.0",
     "gulp-clean": "^0.3.1",
     "gulp-clean-css": "^2.0.4",
     "gulp-concat": "^2.6.0",