MVP: Manual Sleep Tracking App

There are _many_ apps https://github.com/dwyl/sleep/issues/8 and wearable devices https://github.com/dwyl/sleep/issues/7 that people can use for sleep-tracking.
The issue is that these have a _cost_ and the people using them have **no control of their data**.

I want to build the _bare minimum_ interface for capturing/tracking sleep.
At it's most basic, a sleep tracker is just a stop-watch https://github.com/nelsonic/stopwatch
But rather than simply _discarding_ the **`start`** and **`stop`** times, we record them.

# Todo

+ [ ] Sketch the most basic interface for capturing data
+ [ ] Should be "Dark Mode" by `default` to minimise LED light from device. i.e. light text on a dark background
+ [ ] Should be Mobile First as this is the device _most_ people look at _last/first_ thing.
+ [ ] Describe the schema for storing the data including person_id using `auth_plug` for authentication!
+ [ ] Build a Basic Phoenix App to capture **`start`** and **`stop`** times for sleep
+ [ ] Integrate Authentication via `auth_plug`
+ [ ] Add ability to add Comments [Later!]
+ [x] Deploy to Heroku? https://dashboard.heroku.com/apps/sleepdev
+ [ ] Start _using_ it to capture my own data!

# Dependent on:

+ [x] `auth` deployment: https://github.com/dwyl/auth/pull/173

My plan is to write this out as a _tutorial_ that a _complete_ beginner can follow similar to all of our [others](https://github.com/search?o=desc&q=topic%3Atutorial+org%3Adwyl+fork%3Atrue&s=updated&type=Repositories).