The cron build of travis appears to break master (see) which actually does not (see the same commit). The thing is that in the cron build uses numpy 1.14.0.dev0+d607099 whereas the regular build uses numpy 1.13.1-py36h5bc529a_2. This makes doctests to break due to precission.

Expected:
    0.824...
Got:
    0.825

ping @lesteve