task-build: Write version number for build with commits
task-build: Write version number for build with commits

This will now show up in "ostree admin status".

vrutkovs/vrutkovs.github.io,vrutkovs/vrutkovs.github.io,chergert/gnome-continuous,chergert/gnome-continuous,vrutkovs/vrutkovs.github.io,chergert/gnome-continuous