Should properties not recognized with rtd & karma & mocha & chai

[AdrienLemaire]

Hello,

I created this issue #124, but it might actually be a problem with karma-chai. I'd really appreciate if you could check it out :)

The problem is that some very basic tests with chai/should work, but when I try to do a containEql or throw/throwError, it fails without any traceback (and debugging the values doesn't raise any alarm, they look good).

Thank you for your help!