CI build for Python 3.7 image failing

Hi, I’m currently running tests on my project with Python 3.7 enabled, however Travis seems to fail to load the image. Anyone know if this is a known issue? Link to the build: https://travis-ci.org/Paradoxis/Flask-Unsign/jobs/484723652

Python 3.7 doesn’t work with Trusty. Could you try

dist: xenial

Thanks.