Refactor prototype code

[kennib]

Currently the prototype code is very messy. I can already tell it's starting to slow down progress.
The code should be refactored to make things simpler and easier to understand and reason about.

[kennib]

This is highly related to issue #47 (documentation)

[kennib]

TODO

• Simplify remote data management
• Refactor app update function
• Move view code out of App.elm
• Move navigation code out of App.elm
• Make animation code simpler
• Move swiping events into the elm-swipe package
• Refactor font awesome i tags into an elm package
• Move date, distance, number formatting into a formatting package
• Move Postgrest API requests into an elm package