Shopify/active_merchant — pull request #1261 by duff (2014-06-16 14:58:01+00:00)
Title: Elavon: Make void work for authorizations too

The void operation we had worked for purchases but not for
authoriztions. We were using a CCVOID operation. Now we're using a
CCDELETE operation.

From the Elavon docs:
The `ccvoid` is a transaction that removes a Sale, Credit or Force
transaction from the open batch... The `ccvoid` command is typically
used for same day returns or to correct cashier mistakes.

The `ccdelete` is a transaction that deletes and attempts a reversal on a
Sale or Auth Only Credit transaction.