Updated build process to correctly scope the main file in bower.json

The problem is that the `dist` folder becomes https://github.com/wzr1337/bower-angular-gestures and the `main` property points to an invalid location. If someone something like https://www.npmjs.org/package/main-bower-files, this package won't resolve correctly which defeats the purpose of bower.

This pull request addresses that issue by processing the `bower.json` file instead of just copying it. This way if someone does a `bower install wzr1337/angular-gestures` (this repository) their stuff will work correctly. If someone does `bower install angular-gestures`, (official way) that will also work correctly.