Add keyword arguments to reverse

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_states/widgets.py

@@ -18,7 +18,11 @@ def widget_transition_events(transition):
 def widget_workflow_diagram(workflow):
     return mark_safe(
         '<img class="img-responsive" src="{}" style="margin:auto;">'.format(
-            reverse('document_states:workflow_image', args=(workflow.pk,))
+            reverse(
+                viewname='document_states:workflow_image', kwargs={
+                    'pk': workflow.pk
+                }
+            )
         )
     )