added (returned #{inspect value})

lib/mock.ex

@@ -190,7 +190,7 @@ defmodule Mock do
           message: """
             Expected call but did not receive it. Calls which were captured:\n\n#{calls}.
             \n
-            Expected call: #{unquoted_module}.#{unquoted_f}(#{unquote_args |> Enum.map(&Kernel.inspect/1) |> Enum.join(",")})
+            Expected call: #{unquoted_module}.#{unquoted_f}(#{unquote_args |> Enum.map(&Kernel.inspect/1) |> Enum.join(",")}) (returned #{inspect value})
           """
       end
     end