COMPAT: blacklist numexpr=2.4.4
close #12489
xref #11915 

Maybe you want to add a short note to the dependencies section of the main `README.md`? We should probably just remove that section and link to the docs so it doesn't fall out of date.
 @TomAugspurger hmm, that is a good point. want to do a (can separate) PR for that?
 Yeah, I'll do one separate.
 thank you sir!
 @jreback : Travis is giving a green light.  Don't know if you intend to add anything else to this PR though.
