reference to not minified version of main file

If this package is used within a build process (e.g. yo web app), referencing minified versions of packages will cause errors during build

This topic has been discussed multiple times... and making this change actually helped me to optimise my web application.

https://groups.google.com/forum/#!msg/twitter-bower/P8TbooJPacs/Qxy40Gcp2o0J

bower/bower#368

and even been adopted in packages like bootstrap:

twbs/bootstrap#9493
Merge pull request #158 from benkroeger/master

reference to not minified version of main file