Renovate: Add "hex" datasource (Elixir/Erlang)

[rarkins]

Example:
https://hex.pm/api/packages/certif

Need to also handle private packages with auth.

[rarkins]

I'd recommend to start by copying from the Cargo datasource structure, and updating to match the hex metadata.

[renovate-bot]

:tada: This issue has been resolved in version 14.14.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[hewsut]

Howdy! We're using Renovate with a NodeJS repo to great success.

We're looking at some new tech in new projects. Does this PR mean Renovate fully supports Elixir/Erlang now?

[rarkins]

@hewsut Elixir/Erlang is not quite supported yet. Supporting a new language means up to three new pieces maybe required:

• datasource
• version scheme
• extract and update functions

So far we have the first 2 merged, which will be common for both mix and rebar, and the last part for Mix is in this PR: https://github.com/renovatebot/renovate/pull/3248

If you subscribe to it then you'll know when Mix is ready for resting. Rebar will come after in a separate PR.

[hewsut]

Subscribed, looking forward to it!

We are happy paying customers. Great job building all this out so thoughtfully.