automate author, licenses.type

+ Not sure how to insert all the authors, but poor Brian got left out of the [package.json](https://github.com/helpers/banners/blob/master/package.json) :(
+ Not everyone uses MIT, but a few use multiple...
+ Hard coded year & left comment per #1

? Not sure if `pkg.description` should be part of the big banner.

BTW, interesting use of `.join`.