Update lint-unit to v3 #154

Job	Run time
lint-unit / markdown-link-check	17s
lint-unit / check-metadata	0s
lint-unit / cookstyle	35s
lint-unit / markdownlint-cli2	15s
lint-unit / rspec	41s
lint-unit / yamllint	11s
integration (amazonlinux-2, default)	1m 20s
integration (centos-7, default)	1m 16s
integration (centos-8, default)	33s
integration (debian-9, default)	1m 29s
integration (debian-10, default)	1m 25s
integration (fedora-latest, default)	1m 57s
integration (opensuse-leap-15, default)	1m 53s
integration (ubuntu-2004, default)	1m 47s
integration (ubuntu-2104, default)	30s
	14m 9s

Provide feedback