Drop Erlang R16 support

[janl]

No description provided.

[wohali]

1. remove this line from .travis.yml
2. this breaks Jenkins, because Step 1 (which builds the dist tarball) runs in couchdbdev/ubuntu-trusty-erlang-default which is 16B03.

I need to build a new Docker container that has R17 in it instead, a couchdbdev/ubuntu-trusty-erlang-17.XX.XX using packages from erlang-solutions. This will be minor changes to apache/couchdb-ci and a docker push after the fact.

Please hold on merging this until that's done and I can run a jenkins test. I hope to get to it later today.

[wohali]

See comment

[janl]

Please hold on merging this until that's done and I can run a jenkins test.

You’ve got it.

[janl]

remove this line from .travis.yml

Done.

[wohali]

@janl I'm building the image today - and will do a separate push to an updated Jenkinsfile to master so that this PR won't break the build. I'll update back when ready.

+1 to dropping 16B03* support.

[wohali]

We'll make it for 2.2.0.

[wohali]

Once #1438 lands this can merge.

[wohali]

As to the discussion part, I know @rnewson was ready to drop 16B03 a long while ago, and there was general agreement on IRC that this is "the right thing to do." Since packages no longer rely on the system-provided Erlang, there is little motivation for us to support really old Erlangs anyway...but shifting to a "you need {latest|latest-1} Erlang release" approach is probably best saved for a 3.0 IMO.

[nickva]

+1