This PR resolves a small bug in the updatenotification module if a local
git repo is ahead of the remote (for example I have made local commits
for my personal needs).
Currently, if `git status -sb` reports a status like: `##
master...origin/master [ahead 2]` then updatenotification treats this as
though it's "behind".
This PR uses a single Regex to match `git status -sb` output and uses
capture groups to extract info to populate the `gitInfo` object to avoid
needing to do string manipulation to extract this information.
Co-authored-by: Dario Mratovich <dario.mratovich@outlook.com>