new_users fields are more explicit

also easier to work with given current goals

server/migrations/2020-02-07-231841_new_users/up.sql

@@ -1,6 +1,6 @@
 -- Used only for those that have been given an invite and are currently using that invite
 CREATE TABLE IF NOT EXISTS `new_users` (
-    `token` bigint NOT NULL,
-    `invite_id` bigint NOT NULL,
+    `token` VARCHAR(255) NOT NULL,
+    `invite_id` bigint UNSIGNED NOT NULL,
     PRIMARY KEY(`token`)
 );