Add bower.json

This file allows this package to be installed using Bower. The package
has already been registered as `jquery-waypoints` in the Bower package
registry. It can now be installed by executing:

  bower install jquery-waypoints

More information on Bower can be found at:

  https://github.com/bower/bower
  http://bower.io
Merge pull request #200 from lencioni/bower

Add bower.json