如何让Composer从GitHub的主分支中下载一个包的最新提交?

I am trying to get Composer do download the latest commit for the Behat/MinkSelenium2Driver package. That particular repo only has a master branch. I have tried every method I can think of, including deleting the files and letting it pull them back in, to get it to work but it doesn't.I am trying to get Composer do download the lat