Implement sign up and sign in functionality

Steps completing the implementation of the sign up and sign in features include the following:

* Implement [Monban](https://github.com/halogenandtoast/monban) and use [Monban Generators](https://github.com/halogenandtoast/monban-generators)
* Edit homes#show
* Create sign up and sign in forms in partials
* Make dashboards controller and show view