[Bug 875418] Move settings_test back to root.

This is imported by another package, so we don't get to control where it
lives. Maybe this means the other package needs changing.
[Bug 875418] Make ES index names functions.
Added API for oSUMO.

For more information, see https://github.com/mozilla/kitsune/pull/1444

Added language indexing.

Added URL for get language.
Some changes after feedback.