@astrofrog, @bsipocz: The python 3.5, numpy 1.13, astropy LTS job is failing with seg faults trying to compile the cython files. Any idea what's going on there?

https://travis-ci.org/astropy/photutils/jobs/568857136#L3062

weird, as with a quick glance I don't see any version number differences with the installed dependencies.

Very strange, I'll try on my Linux desktop shortly.

@astrofrog Did you find anything? I'm going to start digging into this. I'm planning to release 0.7 today (🤞) and I'd like to include this if possible.

@larrybradley - testing now

Many thanks! I haven't started on this yet.

@astrofrog This is ready for final review.

I've implemented the requested changes and the test pass now. The astropy-dev test failure is unrelated. Thanks again, @astrofrog.