refactor(test): Remove old testing harness

Now all tests have been converted to gtest and the old testing utility
code is not used anywhere

tests/common/test.hpp

@@ -1,40 +1,3 @@
-//
-// Copyright (c) 2016 Krzysztof Jusiak (krzysztof at jusiak dot net)
-//
-// 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)
-//
 #pragma once
 
-#include <cstdio>
-#include <cstdlib>
-
 #include "gtest/gtest.h"
-
-#define expect(...) \
-  (void)((__VA_ARGS__) || (expect_fail__(#__VA_ARGS__, __FILE__, __LINE__), 0))
-#define static_expect(...) static_assert((__VA_ARGS__), "fail")
-
-void expect_fail__(const char* msg, const char* file, int line) {
-  std::printf("%s:%d:%s\n", file, line, msg);
-  std::exit(-1);
-}
-
-template <char...>
-struct test {
-  template <class Test>
-  bool operator=(const Test& test) {
-    test();
-    return true;
-  }
-};
-
-#if defined(__clang__)
-#pragma clang diagnostic ignored "-Wgnu-string-literal-operator-template"
-#endif
-
-template <class T, T... Chars>
-constexpr auto operator""_test() {
-  return test<Chars...>{};
-}