allow request options overrides and add fetchPDF method for invoices
fetch invoices for an account
fix PUT functions, automatic body vs qs
update href on id change
Merge branch 'master' of github.com:ceejbot/recurring
quickly hack some new methods on the account in for adjustments + invoice
Merge pull request #1 from simontabor/adjustments

Adjustments
Merge pull request #6 from simontabor/master

allow request options overrides, add fetchPDF method for invoices, add getInvoices for account