send discount amount to avalara

try with positive number and string

set discounted on line item level

get rid of the absolute value

Revert "get rid of the absolute value"

This reverts commit 2d0b0c5933ed0ef49a3c145a938a6c2fed6ae900.

test to insure positive value for discount
Merge pull request #1 from HoyaBoya/fix/discount_amount

send discount amount to avalara