* Divide Windows integration tests into 2 groups.
* Support `none` for `--changed-all-target`.
* Run 2 separate Windows groups on Shippable.
* Only run smoketest and minimal for the group1 job.
* Improve ansible-test inventory handling.
* Fix python 3 re-raise of exception from thread.
* Fix python 3 encoding for windows-integration.
* Run network tests on multiple python versions.
* Run windows tests on multiple python versions.
* Support Shippable delegation using --tox.
* Skip vyos_command on python 3 tests until fixed.
* Add python 3 filtering to local and tox.
* Fix tests to support back to back runs.
* Temporarily test networking with python 2.7 only.
Running the tests back to back causes intermittent test failures
which need to be addressed before we can test multiple versions
in a single test run.