Remove debug printout in test case

test/gradualizer_highlight_tests.erl

@@ -19,14 +19,14 @@ prettyprint_and_highlight_test() ->
                  "        ^^^^^^^^^^^^^^^\n",
                  lists:flatten(Pretty)).
 
+%% Tests the special form {clauses, [...]} which doesn't have any annotation.
 prettyprint_and_highlight_fun_test() ->
     Expr = {atom, 1, foo},
     Forms = [{function, 1, f, 0,
               [{clause, 1, [], [],
                 [{'fun', 1, {clauses, [{clause, 1, [], [],
                                         [Expr]}]}}]}]}],
     Pretty = gradualizer_highlight:prettyprint_and_highlight(Expr, Forms, _Color = false),
-    io:format(user, "~n~s~n", [Pretty]),
     ?assertEqual("f() -> fun () -> foo end.\n"
                  "                 ^^^\n",
                  lists:flatten(Pretty)).