I’ve got a private Github repo, so unluckily I cannot share a link. But I’ll try to explain my problem in detail.
I already posted this question on stackoverflow but I thought it might be too specific to ask there. Thus I decided to also create a new topic here. 
All details are provided in the linked question. When running pytest locally from a console, all tests pass. When trying to use Travis CI, the first two tests (which don’t require loading the data tables) pass. The rest of the tests requires loading the data tables. All fail while trying to do so.
Any hint on how to solve this issue?
Many thanks in advance!
Best regards,
Johannes
edit:
resolved thanks to a comment on stackoverflow!
There seem to be differences in os.path.abspath between Windows and Linux…