Fix key name

Author: Steven Nemetz

main.tf

@@ -10,7 +10,7 @@ module "enabled" {
 
 resource "github_membership" "this" {
   count    = "${module.enabled.value ? length(var.users) : 0}"
-  username = "${lookup(var.users[count.index], "name")}"
+  username = "${lookup(var.users[count.index], "username")}"
   role     = "${lookup(var.users[count.index], "role", "member")}"
 
   # member or admin