Upgrade quickbooks-ruby
Turn on Quickbooks sandbox mode in the test interface
Get new fields from Quickbooks Online

- Refactor the code a bit to make it more clear what is happening.
- Just return XML from the Monkey-patched code, and then turn that into
  a hash in the service code.
- Convert all the names from Quickbooks to lowercase to reduce issues
  related to that.
- Fix which values we are pulling for revenue and expenses, add several
  new fields.
Fix spec due to change of method call order
Make sure we return 0 for values that aren't found
Add example XML and a spec for QBO
Merge pull request #35 from 25-ventures/feature/qbo-new-fields

Feature/qbo new fields