use keyword methods

lib/policy_service_web/plugs/authorize_roles.ex

@@ -31,7 +31,11 @@ defmodule PolicyServiceWeb.Plugs.AuthorizeRoles do
 
   @impl Plug
   def call(conn, opts) do
-    if authorized?(conn, opts.roles_claim, opts.required_permissions) do
+    if authorized?(
+         conn,
+         Keyword.get(opts, :roles_claim),
+         Keyword.get(opts, :required_permissions)
+       ) do
       conn
     else
       conn