Bumped dependences to latest versions

Author: robneu

package.json

@@ -15,20 +15,20 @@
     "url": "https://github.com/cipherdevgroup/cipher-plugin-config.git"
   },
   "dependencies": {
-    "autoprefixer": "6.x",
+    "autoprefixer": "9.x",
     "grunt": "~1.x",
     "grunt-contrib-clean": "1.x",
     "grunt-contrib-concat": "1.x",
     "grunt-contrib-copy": "1.x",
     "grunt-contrib-cssmin": "2.x",
-    "grunt-contrib-imagemin": "1.x",
-    "grunt-contrib-uglify": "2.x",
+    "grunt-contrib-imagemin": "2.x",
+    "grunt-contrib-uglify": "3.x",
     "grunt-contrib-watch": "1.x",
     "grunt-newer": "1.x",
     "grunt-postcss": "0.x",
     "grunt-replace": "1.x",
     "grunt-rtlcss": "2.x",
-    "grunt-sass": "2.x",
+    "grunt-sass": "3.x",
     "grunt-version": "1.x",
     "grunt-wp-i18n": "1.x",
     "time-grunt": "1.x"