Update ruamel.yaml to 0.17.21#64

pyup-bot wants to merge 1 commit intomasterqbicsoftware/rmageddon-cli:masterfrom

pyup-update-ruamel.yaml-0.16.10-to-0.17.21qbicsoftware/rmageddon-cli:pyup-update-ruamel.yaml-0.16.10-to-0.17.21Copy head branch name to clipboard