This is the best solution that I can think of right now. Sure, it's not
so great to pass a property down from the page component. But at least
it fixes the storybook story, which is something.
This will allow us to use this.$scrollTo in components. I'm now also
using this in the mixin. With so many `this`s it gets horribly
difficult to properly test the mixin in isolation. So I decided to test
the mixin on the component directly.
