kernel.json path is wrong for macOS
kernel.json path is wrong for macOS

`~/.local/share/jupyter/kernels/gopherlab` is the location for Linux, but not macOS. This should be `~/Library/Jupyter/kernels/gophernotes/kernel.json`.
muicoder/gophernotes,gopherdata/gophernotes,muicoder/gophernotes,muicoder/gophernotes,gophergala2016/gophernotes