Vantiv (Litle) Adds account updater functionality

[mwhagedorn]

THIS PR IS ON HOLD DUE TO ISSUES WITH MBTA and Vantiv
see https://www.notion.so/chargify/Vantiv-Account-Updater-Project-2018-f150c24059cc4ac5a746bdde37dbd21e

Vantiv (Litle) adds account updater functionality to gateway. This code is looking for the appropriate items in the gateway response which can be used to update expired tokens. The only change is looking at the return value and parsing it differently.

See https://github.com/Vantiv/CNP-API/blob/master/reference_guides/Vantiv_cnpAPI_Reference_Guide_API9.14_V1.32.pdf
Account Updater is detailled in section 4.8
Table 2-19 contains test data for accountUpdater

[speric]

@mwhagedorn Do you plan on adding tests for this? Also, are there API docs you can share with us that show how you arrived at your solution?

[mwhagedorn]

not in this project, the unit tests are a complete fail and have been for a long time. The tests are going to be higher up the stack

[speric]

How do we know this works, then?

[mwhagedorn]

we have to have full up integration tests, and thats all that has been done in the past. I am strongly thinking about circling back and fixing the tests for litle at least. The whole suite is a mess, they all fail

[mwhagedorn]

Ok I thought about this all weekend. I think it makes the most sense to fix the unit test suite for litle at least. This code is closest to the bone as far as this change goes and it makes sense to test it there. There will of course be integration test in conduit, etc as well.