Integrate Balanced Payments

Yeah! Let's integrate the Balanced Payments on Neighbor.ly. Here is what we need to get done.

### References
- https://www.balancedpayments.com/
- https://docs.balancedpayments.com/current/?language=ruby
- https://github.com/balanced/balanced-ruby

### Concerns
- Checkout process for contributors should be basically the same as the current system, all on site.
- We will have payments in more than one place, for example, on matching system.

### TODO
- [x] Create a shared test Balanced account using a [at]neighbor.ly email.
- [x] Transfer project contributions to project owner.
- [x] Project owner needs to supply ACH information.
- [x] Remove the f****** current code that makes the calc of the fees.
- [x] User should be able to opt out the payment fee.
- [x] Store creditcard processing fees in database.
- [x] Add Billing Address information on payment page for credit card method.
- [x] Add Billing Address information on payment page for bank transfer method.
- [x] Remove Paypal as payment option.
- [x] Remove Authorize.net credit card payment option.
- [x] Remove Authorize.net echeck payment option.
- [x] Require user to be logged in on payment engines.
- [x] Remove rake task `check_echeck`