change to use jquery's esprima harmony branch

this is more up to date than that from ariya

package.json

@@ -30,7 +30,7 @@
     "esformatter": "~0.5.0",
     "esformatter-braces": "~1.0.0",
     "esformatter-var-each": "~1.0.0",
-    "esprima": "ariya/esprima#harmony",
+    "esprima": "jquery/esprima#harmony",
     "falafel": "~0.3.1",
     "glob": "~4.4.0",
     "rc": "~0.6.0",