Possible fix V2

moto/elbv2/urls.py

@@ -1,10 +1,11 @@
 from __future__ import unicode_literals
 from .responses import ELBV2Response
+from ..elb.urls import api_version_elb_backend
 
 url_bases = [
     "https?://elasticloadbalancing.(.+).amazonaws.com",
 ]
 
 url_paths = {
-    '{0}/$': ELBV2Response.dispatch,
+    '{0}/$': api_version_elb_backend,
 }