on OSX, tests fail

[andy5995]

Tests fail on OSX when they are enabled ( -DBUILD_ZETAGLEST_TESTS=ON)

https://travis-ci.org/ZetaGlest/zetaglest-source/jobs/429367334#L2012

Scanning dependencies of target zetaglest_tests
[ 97%]Building CXX object source/tests/CMakeFiles/zetaglest_tests.dir/test_runner.cpp.o
[ 97%]Building CXX object source/tests/CMakeFiles/zetaglest_tests.dir/shared_lib/graphics/font_test.cpp.o
In file included from /Users/travis/build/ZetaGlest/zetaglest-source/source/tests/shared_lib/graphics/font_test.cpp:12:
In file included from /usr/local/include/cppunit/extensions/HelperMacros.h:9:
/usr/local/include/cppunit/TestCaller.h:121:28:error:no member named 'bind' in namespace 'std'; did you mean 'find'?
            m_test_function( std::bind(test, m_fixture) )
                             ~~~~~^
/Applications/Xcode-9.2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:888:1:note:'find' declared here
find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
^
In file included from /Users/travis/build/ZetaGlest/zetaglest-source/source/tests/shared_lib/graphics/font_test.cpp:12:
In file included from /usr/local/include/cppunit/extensions/HelperMacros.h:9:
/usr/local/include/cppunit/TestCaller.h:138:28:error:no member named 'bind' in namespace 'std'; did you mean 'find'?
            m_test_function( std::bind(test, &fixture) )
                             ~~~~~^
/Applications/Xcode-9.2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:888:1:note:'find' declared here
find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
^
In file included from /Users/travis/build/ZetaGlest/zetaglest-source/source/tests/shared_lib/graphics/font_test.cpp:12:
In file included from /usr/local/include/cppunit/extensions/HelperMacros.h:9:
/usr/local/include/cppunit/TestCaller.h:155:28:error:no member named 'bind' in namespace 'std'; did you mean 'find'?
            m_test_function( std::bind(test, fixture) )
                             ~~~~~^
/Applications/Xcode-9.2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:888:1:note:'find' declared here
find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
^
In file included from /Users/travis/build/ZetaGlest/zetaglest-source/source/tests/shared_lib/graphics/font_test.cpp:12:
In file included from /usr/local/include/cppunit/extensions/HelperMacros.h:9:
/usr/local/include/cppunit/TestCaller.h:155:23:error:no matching function for call to 'find'
            m_test_function( std::bind(test, fixture) )
                             ^~~~~~~~~
/Users/travis/build/ZetaGlest/zetaglest-source/source/tests/shared_lib/graphics/font_test.cpp:33:2:note:in instantiation of member function 'CppUnit::TestCaller<FontTest>::TestCaller' requested here
        CPPUNIT_TEST( test_LTR_RTL_Mixed );
        ^
/usr/local/include/cppunit/extensions/HelperMacros.h:299:15:note:expanded from macro 'CPPUNIT_TEST'
        ( new CPPUNIT_NS::TestCaller<TestFixtureType>(    \
              ^
/usr/local/include/cppunit/Portability.h:107:21:note:expanded from macro 'CPPUNIT_NS'
# define CPPUNIT_NS CppUnit
                    ^
/Applications/Xcode-9.2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/algorithm:888:1:note:candidate function template not viable: requires 3 arguments, but 2 were provided
find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
^
4 errors generated.
make[2]: *** [source/tests/CMakeFiles/zetaglest_tests.dir/shared_lib/graphics/font_test.cpp.o] Error 1
make[1]: *** [source/tests/CMakeFiles/zetaglest_tests.dir/all] Error 2
make: *** [all] Error 2