[Tree] Update test configuration

...to account for new dependency on Zepto (and its necessary
shim.)

test-main.js

@@ -66,6 +66,9 @@ requirejs.config({
         },
         "moment-duration-format": {
             "deps": [ "moment" ]
+        },
+        "zepto": {
+            "exports": "Zepto"
         }
     },