- Remove Jessie from allowed failures in TravisCI (the problem with the image download was resolved).

- Disable testing on Python 3.5, it isn't supported by Molecule and doesn't seem to gonna be supported anytime soon.

- Remove OpenBSD 5.9 platform from testing, it never worked and it's not supported upstream anymore now that OpenBSD 6.1 was released.

- Don't cache .tox, packages aren't updated.

- Allow up to 45 minutes for molecule test (workaround builds that were killed because no output was received for 10 minutes, usually APT installations).

- Stop testing with Docker containers, they're only a good fit for a very limited use (cli applications, not services or system-level) and the speed of testing doesn't justify the work needed.

- Removed `--quiet` from the piprot check to see which packages are out
of date (check still works the same).
- Test on Python 3.5 and not 3.4 because Ansible is tested on 3.5 and
later.

- Replaced Debian Wheezy and Jessie Vagrant boxes.

didn't help.

This reverts commit e1804d8d.

- Try using Python 3.4 as it seems to be the oldest Python 3 version on which pre-commit tests (according to their Travis CI).

- Build on my supported platforms (some don't have properly working Vagrant boxes so they're allowed to fail).

- Caching the entire virtualenv in Travis CI has proven to cause issues, caching just pip's cache directory.