Use new /release/versions/DIST API endpoint

[mickeyn]

Replace the Elasticsearch query sending with a call to the new
API endpoit.

This change also fixes the related tests and simplifies the
way 'verisons' query was called.

[coveralls]

Coverage remained the same at 43.665% when pulling e6151d0 on mickey/release_versions_endpoint into 93aecb9 on master.

[oalders]

👍

[haarg]

This seems to take one of the asynchronous calls and makes it blocking instead. That doesn't seem like a good change.

The API being used for the async calls is not the best. Maybe we need to change that to make it easier to manage?

[mickeyn]

@haarg I noticed that, but in this case it didn't seem to matter.

I agree the way we currently do the async calls is way too complicated and hard to maintain.

In this specific case i took a fast, limited query (size=>250) which was also used in other places where async wasn't needed - so i don't believe the performance is affected in a user-noticeable way.

We can restore the versions call into the async calls, but i do want to clean that code first as you suggested.

[mickeyn]

I'm going to revert this commit as I see it's responsible for tests currently breaking in master (odd...)

[mickeyn]

@haarg @oalders I reverted this commit and will work on a new one soon
#1911