Travis CI fails in master branch

[raveit65]

Currently Travis-CI i broken in caja master branch and probably everywhere in our repos. See https://app.travis-ci.com/github/mate-desktop/caja/jobs/616398552#L258
The command "./docker-build --name ${DISTRO} --config .build.yml --install" failed and exited with 1 during .
At this part docker-build from mate-devs repo starts to download the docker image.
See in a successful build https://app.travis-ci.com/github/mate-desktop/caja/jobs/615673703#L208

./docker-build --name ${DISTRO} --config .build.yml --install
>>> [docker pull fedora:latest] <<<
latest: Pulling from library/fedora

I tried something in travis-pip-update branch but without success.
Sadly i do not get an verbose output at this point, in result i will wait some days to be sure that the connection between travis-ci and dockerhub isn't broken or something has changed.