Fix the link to run_e2e_workflow.py script (kubeflow#1114)

prow_config.yaml

@@ -1,5 +1,5 @@
 # This file configures the workflows to trigger in our Prow jobs.
-# see kubeflow/testing/py/run_e2e_workflow.py
+# see https://github.com/kubeflow/testing/blob/master/py/kubeflow/testing/run_e2e_workflow.py
 python_paths:
   # Need to place kubeflow/testing in front of kubeflow/testing so that the package can
   # be correctly located.
@@ -30,4 +30,4 @@ workflows:
       test_endpoint: true
       # The path for the config should depend on the commit we are testing manifests on.
       # so we use the local path which will be checked out to the correct commit
-      config_path: "{srcrootdir}/kubeflow/manifests/kfdef/kfctl_gcp_iap.yaml"
+      config_path: "{srcrootdir}/kubeflow/manifests/kfdef/kfctl_gcp_iap.yaml"