Instagram support

This is not done but basics are there. Pulls ~20 pictures with #sfcycling. Links to original Instagram url in a new tab. 

Stuff I would have liked to add (but can't guarantee when I can):
- better styling
- overlay effect that displays image info
- tweak images to be larger
- maybe remove the pink border thing and just make the whole home page a big grid
- figure out how to cache/resolve the JSON request for better UX
- put the JS file hooking up the JSON to the DOM somewhere other than public/