Fixes #17516 - Update jquery to 1.12 to fix XSS

Affected versions of the package (< 1.12) are vulnerable to Cross-site
Scripting (XSS) attacks when a cross-domain ajax request is performed
without the dataType option causing text/javascript responses to be
executed.

jquery/jquery#2432 for more information

package.json

@@ -44,7 +44,7 @@
     "events": "^1.1.1",
     "flux": "^2.1.1",
     "ipaddr.js": "~1.2.0",
-    "jquery": "~1.11.0",
+    "jquery": "~1.12.0",
     "jquery-flot": "~0.8.3",
     "jquery-ujs": "~1.2.0",
     "jquery.cookie": "~1.4.1",