Unmount on Mac

[nickpater]

Hello! Great project, really useful!

I've had an issue with the unmount on my mac, because the application couldn't find the mounted dmg. So the application would just update to the latest mounted version (not the latest downloaded version).

I changed the line 'exec('hdiutil unmount ' + filename, function(err){' in updater.js:87 to 'exec('hdiutil unmount /Volumes/'+path.basename(filename, '.dmg'), function(err){' and that seems to solve the problem.