Transferred from https://github.com/travis-ci/travis-ci/issues/582.
Bionic 18.04 was released in April 2018.
Please add Bionic to Travis CI.
It’s good Xenial 16.04 was recently added (https://blog.travis-ci.com/2018-11-08-xenial-release).
However, Trusty 14.04 will be EOL soon in April 2019 so it’ll be good to have the both supported Ubuntu releases available.
(Python 3.7 not added for bionic images is for Python 3.7 on Bionic, but this is more general issue.)