feat: drop six

BREAKING CHANGE: not compatible with python2 anymore.
5 jobs for !14 with topic/default/drop-python2 in 3 minutes and 51 seconds (queued for 4 minutes)
latest detached
Status Job ID Name Coverage
  Lint
passed #289172
check-manifest

00:00:27

passed #289171
flake8

00:00:24

passed #289174
safety

00:00:48

passed #289173
yamllint

00:00:30

 
  Tests
passed #289175
py3

00:02:07