New badges (Libre, Starter, Premium, Ultimate)

For #1906 (closed) - STEP 1

Based on https://about.gitlab.com/handbook/marketing/product-marketing/#9-types-of-users, we'll update the labels per Sid's request on slack.

If we keep the same layout, the badges will look huge. The layout I'm proposing is:

• Make them display below the header, not beside it.
• Make the font of the badge smaller

Besides that, we need to decide if we want:

1. Multiple badges, one of each tier (as it currently is): So, instead of "ce, ees, eep, eeu", we would have "libre, starter, premium, ultimate"
2. One single badge, like "Premium" for EE Premium

• 2.1 What's the single badge for "CE"? Can be "Libre" or "All"

Check how they look:

Review Apps from !9645 (merged): https://new-product-badges.about.gitlab.com/2018/01/22/gitlab-10-4-released/