CML v0.4.5

• Runners not unregistering due to camelCase (#585) …
• ssh_private is valid in TF (#584)
• Install ping on Docker images (#579) …
• Fix job with no steps in test-deploy.yml
• Allow access to secrets for external contributors (#574) …
• Install python-dev in the docker (#572) …
• bump version, merge branch 'devel'
• Improve GitLab API finder error handling (#569)
• Unmask catch-all token exceptions (#563) …
• chat ops safety (#558)
• imgs: (re)move & update (#555)