Add missing comma to bower file.

bower.json

@@ -3,7 +3,7 @@
   "description" : "Unofficial bootstrap switch",
   "version": "1.9.0",
   "main": [
-    "build/js/bootstrap-switch.js"
+    "build/js/bootstrap-switch.js",
     "build/css/bootstrap3/bootstrap-switch.css"
   ],
   "ignore": [