tests fail on appveyor builds #392
Description
The tests starting failing on the windows python 3.4 appveyor builds due to problems with the scipy matlab io functionality. I don't think it has anything to do with pvlib itself, but I do think we'll need to change something about our test environment. I'm guessing that updating the test environment to python 3.6 will work.
See #389 and https://ci.appveyor.com/project/wholmgren/pvlib-python-fv2to/build/1.0.840/job/4bk4whljv8ojjuwt