Merge branch 'feature/docs/bump-copyright' into 'master'

docs: Bump copyright year to 2021

See merge request ungleich-public/cdist!1009
3 jobs for master in 2 minutes and 28 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #10398
pycodestyle

00:00:43

passed #10397
shellcheck

00:00:51

passed #10399
unit_tests

00:00:53