Due WorldEdit incompatibility on versions below 1.13 I've added a new selecting system.

You can still use WorldEdit for 1.13. For versions below 1.13 you can use /sr cptool and you will receive a stick that will work the same way as WorldEdit for selecting checkpoint areas.

You DON'T need this update if you are using 1.13 or already have your arenas.

• Added /sr cptool command to add checkpoints on non-1.13 versions.
  • Requires sr.admin permission.
• Updated dependencies.

Next update may be a huge one, this should be the stable version for all server versions, worldedit dependency may be full removed soon.