Push to card dashboard changes

PR for #1218 and #1215

Variables pending [API specs](https://github.com/balanced/balanced-api/pull/580) to be merged in:
- [x] `can_credit` on `models/card.js`
- [ ] push to card fees on `templates/invoices/invoice.hbs` (pending https://github.com/balanced/balanced-api/issues/623)
- [x] test
- [x] change the message "Credit is processing, funds will be available the next business day unless there is an issue with the bank account" to "Funds will be available within 2-3 business days"