I figured it out. Thanks.

I have the same problem. Can you tell me how you fixed it?

I can't quite remember. Maybe I dropped some python versions. You can see the working files here:

https://github.com/pydy/pydy/pull/315/files

And maybe compare to yours.

In that PR I wrote:

The compilation was failing due to a mismatch in the installed miniconda python version (i.e. Miniconda35 was being downloaded when I thought it was Miniconda3.4).

@moorepants @giampaolo - #294 is the relevant issue, and the actual fix was done in ci-helpers in astropy/ci-helpers#29

Hope it helps.

Btw you can use ci-helpers, too if you like, it does take care of these standard setup issues. Usage example is in the .travis.yml and appveyor.yml, and an example for a bit more complicated matrix can be found in astropy's travis.yml.