v0.4.1

Security fixes

• Patch Kubernetes for CVE-2020-8558 ([#977])
• Update tough to 0.7.1 to patch CVE-2020-15093 ([#979])

OS changes

• Add a new aws-k8s-1.17 variant for Kubernetes 1.17 ([#973])
• Confine chrony, wicked, and dbus-broker via SELinux, and persist their state to disk ([#970])
• Persist systemd journal to disk ([#970])
• Add an API for OS updates ([#942], [#959], [#986])
• Add migration helpers to add / remove multiple settings at once ([#958])
• Fix SELinux policy to allow CSI driver mounts and transition used by Kaniko ([#983])
• Update to new repo URL via migration to ensure signed migration support ([#980])

Build changes

• Fix environment variable override for build output directory ([#963])
• Update .dockerignore to account for the new build output directory structure ([#967])
• Remove the preview-docs task from Makefile ([#969])

Documentation changes

• Document new update APIs and add associated diagrams ([#962])
• Add ap-south-1 to supported regions ([#965])
• Fix storewolf's documentation and usage message as it expects a semver value ([#957])