My sense is that we should do two things:

1. Drop support for versions of CPython that are EOL.
   • https://docs.python.org/devguide/index.html#branchstatus
2. Be explicit (not implicit) about the versions of CPython that we support.

    "Programming Language :: Python :: 2.7",
    "Programming Language :: Python :: 3.4",
    "Programming Language :: Python :: 3.5",
    "Programming Language :: Python :: 3.6",
    "Programming Language :: Python :: 3.7",

Or maybe shadow requests https://github.com/requests/requests/blob/master/setup.py#L90

Drop support for versions of CPython that are EOL.

Sure thing. I'll approach this in a different PR as it will be a much bigger change.

Be explicit (not implicit) about the versions of CPython that we support.

Is this a request for a change? This PR is being explicit. It documents explicit Python 3.6 support. I didn't include Python 3.7 as this repo is not yet testing against Python 3.7. Would you like my to add the 3.7 classifier as well?

Looks like 3.7 is being handled in #366

Drop support for versions of CPython that are EOL.

Started this process in #371

That approach makes sense to me. I've merged in #367 and will merge in #371 to adjust the Travis runner and code to reflect that support.

This and #366 both cover .travis.yml / setup.py changes for 3.6/3.7, but neither seem to fix the existing test failures. Is that something you two might be interested in making progress on? I think once we have tests working and #368 merged in, we can do a release cut and start looking at 1.0 after we've burned down more of our bug balance.

@cclauss re implicit/explicit do you mean to say that we should avoid the ":: 2" and ":: 3" trove classifiers?

The ":: 2" and ":: 3" document that Python 2 and Python 3 support exists in some capacity. I think they should remain.

neither seem to fix the existing test failures.

I can start investigating these. Do you know why Travis CI is no longer running?

I rebased to resolve merge conflicts.