using S3. Do not keep originals
for avatars/headers, resize avatars down to 120x120 instead of 300x300. Set cache headers on S3 stuff, also
make it private (aka only accessible via expiring links to prevent hotlinking)
resources that require a user context vs those that don't (such as public timeline)
/api/v1/statuses/public -> /api/v1/timelines/public
/api/v1/statuses/home -> /api/v1/timelines/home
/api/v1/statuses/mentions -> /api/v1/timelines/mentions
/api/v1/statuses/tag/:tag -> /api/v1/timelines/tag/:tag