Import/Export CSV

Might need to add the ability to import CSV files, depending on whether they've already used Excel to make their inventory.
You could use `Location.find_or_create` here, which will go ahead and create it if it didn't already exist, that way you don't have to save it later.  In the case where the location already existed, you're currently doing an unnecessary database write.  No point in saving if it already existed and you didn't change it.