Add settings UI

Summary:
Adds a simple UI for editing settings, a reducer and persistance config for the data.
These values aren't yet used for anything.

Reviewed By: passy

Differential Revision: D17684490

fbshipit-source-id: e76ac43ffa17d3606e59f4a1ccb940e8d9fbd9e8

src/utils/icons.js

@@ -46,6 +46,9 @@ const ICONS = {
   profile: [12],
   target: [12],
   bird: [12],
+  settings: [12],
+  directions: [12],
+  'dots-3-circle-outline': [16],
 };
 
 // Takes a string like 'star', or 'star-outline', and converts it to