Fix issue #154

[kaelancotter]

This fixed the type error for me in python 2.7. I'll work on and submit the CI fixes in a seperate PR.

[guillaumeeb]

Ok, I'm probably being too meticulous, but I would prefer to have the int() call around math.ceil(). Does this makes sens to you?

[kaelancotter]

Moved. Your code base your call. LMK if/how you'd prefer this orchestrated if a single commit is significantly preferred.

[guillaumeeb]

We're squashing commits upon merge, so it's fine. I haven't checked #157 Travis output, but if It correctly catched the bug fixed here, It would ne good to retrigger the Travis check with an empty commit for example.