v0.0-460-ga1f5475: Travis CI: Add Ubuntu 20.04 LTS (Focal Fossa) (#342)
* Travis CI: Add Ubuntu 20.04 LTS (Focal Fossa) https://releases.ubuntu.com/20.04/ * Add Ubuntu focal to docker-generate.sh * Create Docker/ubuntu-focal/.keepme * Travis CI: allow_failures: OS_VERSION=focal Also, fix Travis CI lint issues. * Use pip on line 155 to install python-gflags * Remove allow_failures