Another attempt to get the tests to pass on Travis-CI

Author: pcreux

lib/active_admin/router.rb

@@ -18,7 +18,7 @@ def apply(router)
       router.instance_exec(@application.namespaces.values) do |namespaces|
         namespaces.each do |namespace|
           root_and_dashboard_routes = Proc.new do
-            root :to => namespace.root_to
+            root :to => (namespace.root_to || "dashboard#index")
             if ActiveAdmin::Dashboards.built?
               match '/dashboard' => 'dashboard#index', :as => 'dashboard'
             end