marge-bot-mesa: add hook for pipeline message
Currently marge-bot's failed pipeline messages provide basic info about the pipeline status and a link to the pipeline. Upstream marge-bot now allows marge's pipeline message to be customized by configuring a hooks directory and adding a pipeline_message.py hook for marge to run.
Add the option for any marge-bot release to configure a hooks directory. Configure marge-bot-mesa to use the hooks directory. This will make marge's comments on failed mesa pipelines more informative and save developers from having to click through the pipeline to find failed jobs and tests.
Related mesa/mesa!32151 (merged)
An example of what it will look like when marge-bot-mesa comments on a failed-pipeline: dbrouwer/mesa!41
Edited by Deborah Brouwer