Updated toolchain to work properly with ES6 syntax

Change-Id: Iefb8bfb20fc57a34beeec136b0a2c4433d951e17
diff --git a/package.json b/package.json
index 5238789..e54a66e 100755
--- a/package.json
+++ b/package.json
@@ -1,22 +1,22 @@
 {
   "name": "Kalamar",
   "description": "Mojolicious-based Frontend for KorAP",
-  "license" : "BSD-2-Clause",
-  "version": "0.27.2",
-  "repository" : {
+  "license": "BSD-2-Clause",
+  "version": "0.27.3",
+  "repository": {
     "type": "git",
     "url": "https://github.com/KorAP/Kalamar.git"
   },
   "devDependencies": {
-    "grunt":                   "^1.0.1",
-    "grunt-contrib-copy":      "^1.0.0",
-    "grunt-contrib-imagemin":  "^2.0.1",
-    "imagemin":                "^5.3.1",
-    "grunt-contrib-jasmine":   "^1.1.0",
-    "grunt-contrib-sass":      "^1.0.0",
-    "grunt-contrib-watch":     "^1.0.0",
+    "grunt": "^1.0.3",
+    "grunt-contrib-copy": "^1.0.0",
+    "grunt-contrib-imagemin": "^2.0.1",
     "grunt-contrib-requirejs": "^1.0.0",
-    "vinyl-fs":                "^3.0.2",
-    "optipng-bin":             "^4.0.0"
+    "grunt-contrib-sass": "^1.0.0",
+    "grunt-contrib-uglify-es": "^3.3.0",
+    "grunt-contrib-watch": "^1.1.0",
+    "imagemin": "^5.3.1",
+    "optipng-bin": "^4.0.0",
+    "vinyl-fs": "^3.0.2"
   }
 }