Valitor update

This is an update to the Valitor integration to the current version of 1.2.4. Valitor is the local VISA branch in Iceland. 

* All parameters have been renamed from Icelandic to English
* The amount is not returned by Valitor so some tests regarding 'gross' were removed
* I have not found a way to run the remote test, I'm not sure how to handle that. Leaving it as is for now.