[WIP] Calculate and display Timezone

### Work in Progress

Pivotal Story: [Calculate and display Timezone](https://www.pivotaltracker.com/s/projects/982890)

We are using value objects because they expose the domain logic more explicitly.
* `Timezone` exposes name and UTC offset.
* `Coordinates` collects data-clump of lat/lng.
* `LastSignInIP` handles getting IP and its graceful null.