crate.io: Remove import task

crate.io has been discontinued and the API no longer responds.
crate.io: Remove from project details page

As the import task fails, the data may be stale and the links only redirect to
PyPI.
crate.io: Don't use crate.io as index for pip

crate.io is discontinued, and PyPI got a nice CDN some time ago, making it
fast and reliable.
crate.io: Remove the crate_url field
docs: CI has moved to Travis
Update translations.
Add i18n to docs.
Use relative URL on version URL to keep CNAME
Bump theme
Bump theme css
Turn the RTD bar red if version is no longer active.
Pass API_HOST into our JS.

This allows us to make sure our dev server is hitting the proper API, like our builds.
Simplify logic.
Basic doc cleanup.
Bump theme
Fix JS to not leak global
Merge pull request #616 from rtfd/notify-old-docs

Turn the RTD bar red if version is no longer active.
Clean up translation listing to not dupe translations.
Fix regroup logic
Damn regroup tag is crazy