Added a gitignore
Added csv to respond_to format for payments
Require csv and defined initial to_csv method
Campaign name is CSV filename
Update CSV header to be more user-friendly
CSV takes into account campaign goal type
Added link to download CSV on payments view
Format for XLS files and registered MimeType
Options for to_csv method
Add XLS to payments view
Display amount and date correctly
fixed collision with payment model
polishing up csv download, foregoing xls download for now