Sometimes we want to create a dive site just based on a name, sometimes we
have both a name and GPS coordinates. Let's make a helper for either case.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This doesn't make the code necessarily more compact, but easier to read
and is consistent with our other patterns.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>