actually the code(at gitHub) you are giving does not using UIPgeviewController its just representation of scrollview as page view even you can see that this code is not using dataSource function of pageiew controller and one more thing i want to say that whatever you are doing in your code is logical and rest of things are depending on the need. may be you can use that code in your project if you want to do.
what ever you are doing is just a feature of UIPageViewController. UIPageViewController showing as the same way you see.
if you want to remove that bouncing you can use UIPageViewControllerTransitionStylePageCurl style