Add rake task for seeding recently viewed data
Update the landing page with the new branding

Make the unauthenticated landing page fall in line with the rest of the
Exercism branding and update it to use the new styles.
Merge pull request #1731 from mattr-/berryify-unauthenticated-landing-page

Update the landing page with the new branding
Tagline-case the tagline

Taglines shouldn't be title-cased.
Delete unused image
Add more data to submit endpoint

I'm not at all happy with how this is being tested, but I haven't decided how to fix it yet
clean up error messages in submit endpoint
Add prototype of looks api endpoint

This has an N+1 (actually, N+2). It's pretty horrible.
Merge branch 'master' of https://github.com/exercism/exercism.io into 1726-paginate-last-viewed
WIP paginate looks 2