Since you have some logic to build the links to the commits in various web UIs, it would be nice if this was available as an ENV variable that other scripts could use.

Namely, I'm trying to fill out the 'url' parameter in the source_commit endpoint for Pivotal Tracker. My current solution is adding an option to our script like `--browser-url http://gitlab.internal/owner/repo/commit/%s`, which is formatted with the GIT_COMMIT variable already supplied by this plugin.