After the ipython 6.0.0rc1 release, the python-fire project ran in to Travis CI failures for internal builds, as noted in google/python-fire#57

It would be helpful to have more readily visible or even proactive advice on how to configure setup.py, pip, and other dependency-management systems for a wide variety of use cases. E.g. how to configure a project to depend on ipython 6 for supported python versions, but version 5 otherwise.