pointing people to the preferred issue tracker

Hi there! Me again :)

I saw that (regarding the previous issue) you quickly moved the entire conversation to github and handled it here. This led me to assume that github is your preferred issue tracker, so I added the "meta" information to the Makefile.PL. As a result, the repository information is going to show next to your dist on metacpan.org, and people will know where to find you. Even if they get to RT but any other means, they will see a giant yellow banner saying that the github issue tracker is your preferred system.

Hope this helps!