Vacation status

[noamross]

The dashboard should allow us to get/set vacation status

• Individual editor vacation status (ideally read off of editor Slack status)
• Project-level vacation status (such as turning off for holiday periods, etc.)

This probably interfaces with other tools, such as

• Making the editorial bot respond with org/editor vacation status
• Changing repo submission issue templates or otherwise (look at how Will Landau sets this for {targets}

[mpadge]

The first of these is done, with results visible at https://ropensci-review-tools.github.io/dashboard/editors.html. The second can be directly adapted from current individual-level code.