AC-2549: update npm underscore to 1.13.2

Author: karyna-t

package.json.sample

@@ -36,6 +36,6 @@
     "squirejs": "~0.2.1",
     "strip-json-comments": "~3.1.1",
     "time-grunt": "~2.0.0",
-    "underscore": "1.13.1"
+    "underscore": "1.13.2"
   }
 }