#1916 - Improving the discount error notices
#1916 - Improving the discount error notices - Forgot Invalid status
#1916 - Forgot the expired status
#1916 - Helps if the expired is in the right condition
Merge branch 'feature/improved-discount-errors' of
github.com:cklosowski/Easy-Digital-Downloads into
cklosowski-feature/improved-discount-errors
Move discount is expired error set into edd_is_discount_active(). #1916