make ping insecure (closes #56)
add refund to credit note logic
add tests
Merge pull request #60 from piesync/insecure-ping

make ping insecure (closes #56)
some formatting
still calculate total invoice amount correctly when a percentage coupon is applied
Merge branch 'master' of https://github.com/piesync/billbo
syntax fix
fix ping
Merge pull request #63 from piesync/refunds

Refunds
Merge branch 'master' into invoice-generation

Conflicts:
	config.ru
	lib/invoice_service.rb