Fixed the Issue thx to rdegges on IRC #express

Basically, being a complete n00b and knowing literally nothing about how
to program, I managed to place the app set-up files in a 'development'
only statement, meaning that req.flash() wasn't being initiated in a
production environment. This means I'll have to read up a lot more on
what environments are (i.e. production vs dev) and how to use them to my
advantage. Ah well, better late than never ;) On to file uploads...