v2.8.1

What's Changed

This is a minor update on v2.8 to avoid unnecessary delete/recreate of compute nodes:

• Avoid compute node replacements due to optional user_data by @MoteHue in #847
• Use 'nodegroups' param in controlled rebuild docs by @MoteHue in #849

For images see release v2.8.

Full Changelog: v2.8...v2.8.1