Update Makefile
On both Mac OS and Debian, it reported '@cp is a invalid command' when issue 'make && make install'. I'm not sure it's the right way to do fix it, but after I delete '@' it just works.
On both Mac OS and Debian, it reported '@cp is a invalid command' when issue 'make && make install'. I'm not sure it's the right way to do fix it, but after I delete '@' it just works.