Use streams from lightweight test

test/exception/insert_exception_tests.cpp

@@ -3,7 +3,6 @@
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 #include "./containers.hpp"
-#include <iostream>
 
 #include "../helpers/helpers.hpp"
 #include "../helpers/invariants.hpp"

test/exception/move_assign_exception_tests.cpp

@@ -8,7 +8,6 @@
 #include "../helpers/invariants.hpp"
 #include "../helpers/random_values.hpp"
 #include "../helpers/tracker.hpp"
-#include <iostream>
 
 #if defined(BOOST_MSVC)
 #pragma warning(                                                               \

test/exception/rehash_exception_tests.cpp

@@ -11,8 +11,6 @@
 #include "../helpers/tracker.hpp"
 #include <string>
 
-#include <iostream>
-
 test::seed_t initialize_seed(3298597);
 
 template <class T> struct rehash_test_base : public test::exception_base