ruamel.yaml broken on Python 3.4 and 3.8-dev

[jayvdb]

https://github.com/moremoban/moban/blob/dev/requirements.txt lists ruamel.yaml>=0.15.5

Python 3.4 test coverage was removed from moban in
bb8c747#diff-354f30a63fb0907d4ad57269548329e3 (without a note in the changelog)

coala still needs it until we do one more release.

When that dep is fixed, another also breaks:

Downloading https://files.pythonhosted.org/packages/a2/6a/a3d20e80ee4fee7c55c022fb28d52239bd01171edd3c137dd1e2ef8b2a20/arrow-0.14.2-py2.py3-none-any.whl
arrow requires Python '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*' but the running Python is 3.4.8
The command "pip install -r tests/requirements.txt" failed and exited with 1 during .

The log https://travis-ci.org/jayvdb/moban/jobs/555568289 doesnt show which test requirement is dependent on arrow.

Potentially, if needed to speed up the builds, put lower support jobs in the matrix to only run on master builds, so that newcomers dont need to worry about them, and decisions can be made to drop them when fixing them is too difficult.

See coala-bears .travis.yml for examples of running job only on master

[jayvdb]

jinja2-time depends on arrow since its inception.
arrow dropped py34 support in 0.14.0 https://github.com/crsmithdev/arrow/blob/master/HISTORY.md

[jayvdb]

Also ruamel.yaml==0.15.5 is broken on Python 3.7, detected by using MINREQ=1.
https://travis-ci.org/jayvdb/moban/jobs/555574463

[jayvdb]

master and dev branches also broken by 3.8-dev , even with the latest version.
https://travis-ci.org/moremoban/moban/builds/556102404

raised upstream https://bitbucket.org/ruamel/yaml/issues/296/another-python-38-dev-compilation-breakage