Log Message:
sysutils/ruby-chef-zero: update to 15.0.4

15.0.4 (2021-01-05)

Merged Pull Requests
* Add missing Webrick dependency to the gemspec #306 (tas50)

15.0.3 (2020-09-28)

Merged Pull Requests
* Added display_name in the normalize_user. #304 (antima-gupta)

15.0.2 (2020-08-21)

Merged Pull Requests
* Optimize our requires #303 (tas50)

15.0.1 (2020-08-13)

Merged Pull Requests
* Optimize requires for non-omnibus installs #302 (tas50)