Added BOOST_TEST_GT and BOOST_TEST_GE.

Just LT and LE are insufficient for testing operator overloads.

test/lightweight_test_gt_fail.cpp

@@ -0,0 +1,20 @@
+//
+// Negative test for BOOST_TEST_GT
+//
+// Copyright 2017 Kohei Takahashi
+//
+// 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 <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    int x = 0;
+
+    BOOST_TEST_GT( x, 0 );
+
+    return boost::report_errors();
+}