doc: update release issue template to include testing day (!5356) · Merge requests · Administrator / sourcegraph · GitLab

Administrator requested to merge fa/release-template into master Aug 23, 2019

Created by: attfarhan

Moves the branch cut to 4 working days before release (this has historically happened 4 working days before at 5pm PT).
Adds the release testing day as 3 working days before release.