Add Content-Disposition and filename for metadata download

mdserver.py

@@ -23,6 +23,7 @@ def sign(domain, eid):
 
     response = Response()
     response.headers['Content-Type'] = "application/samlmetadata+xml"
+    response.headers['Content-Disposition'] = "filename = \"metadata.xml\""
 
     if sha1 in signed[domain]:
         signed_entity = signed[domain][sha1]