Downloaded the most recent version from GitHub. Keep getting this error when trying to 'make', log output below...

Victors-MacBook-Pro:mongo-cxx-driver-master Victor$ make && sudo make install
[ 1%] Building CXX object src/bsoncxx/CMakeFiles/bsoncxx.dir/array/element.cpp.o
In file included from /Users/Victor/Documents/mongo-cxx-driver-master/src/bsoncxx/array/element.cpp:15:
In file included from /Users/Victor/Documents/mongo-cxx-driver-master/src/bsoncxx/array/element.hpp:20:
In file included from /Users/Victor/Documents/mongo-cxx-driver-master/src/bsoncxx/document/element.hpp:20:
/Users/Victor/Documents/mongo-cxx-driver-master/src/bsoncxx/stdx/string_view.hpp:22:10: fatal error: 'core/string.hpp' file not found
#include <core/string.hpp>
^
1 error generated.
make[2]: *** [src/bsoncxx/CMakeFiles/bsoncxx.dir/array/element.cpp.o] Error 1
make[1]: *** [src/bsoncxx/CMakeFiles/bsoncxx.dir/all] Error 2
make: *** [all] Error 2