I added these lines to be future-safe. At the time I wrote the bower file I planned to add an example (html and maybe other files) and grunt support to automate things such as creating the compressed distribution files. With the grunt task `gh-pages` it'd be very easy to update the github page with a newer version (for the demonstration etc.).

It would also help people to get easier involved if they'd not be too familiar with grunt. Though composer support wouldn't be needed, that could be removed. Though these lines don't really hurt.