Add functionality to view list of steps

* The list of steps now pops up on top of the map.
* The steps are put into an array, which is then passed to
  a new view
* The new view iterates over each step and appends it to the
  list-steps div, which is hidden
* Once all of the steps are added, the list is toggled and shows
  up on top of the map.

Issues:
* Right now, the list covers the entire width of the page, and it's
  not possible to get rid of it.

Next steps:
* Make the directions list look better
* Refactor, refactor, refactor--no javascript soup!
* Get rid of the second pin that shows up
* Animate the button to disappear slowly, or only once the locations
  are found
* The screen is sometimes too zoomed to see a pin. Is there a way to
  make the zoom dynamic to include at least one pin?