Bump url-search-params for IE 11

package.json

@@ -11,7 +11,7 @@
     "jshint": "2.8.0",
     "mocha": "2.1.0",
     "mocha-phantomjs-core": "2.0.1",
-    "url-search-params": "0.5.0"
+    "url-search-params": "0.6.1"
   },
   "files": [
     "LICENSE",