Create models to store/retrieve data about hiber

[mcab]

Technically, pages are our models in this case.

[mcab]

Technically (technically), not. Since we're building off of Django, we can simply leverage making Django models, and then use Wagtail's Page model for whenever we want to display that information publicly.

I think that we'll at least want the Bat model exposed as a public page (to show what bats we're keeping track of). Beyond that, not too picky.

[mcab]

Closed by #15, #16, and #21 being merged in.