Fix righttoknow ansible playbook

[ianheggie-oaf]

Describe the bug

Unable to provision development righttoknow, found in

• Resolve ansible-lint errors: Set file permissions for various tasks in Ansible playbooks #470 (comment)

To Reproduce

make vagrant
vagrant up --provision postgresql.test             # 4-5 mins
vagrant up --provision prod.righttoknow.test

Expected behavior

To finish with failed=0

Screenshots/Output

prod.righttoknow.test - FAILED - rbenv install ruby failed on psych (probably missing library)

Additional context