Switch rma to 18.0

Author: pedrobaeza

conf/repo/rma.yml

@@ -15,7 +15,7 @@ rma:
     - "17.0"
     - "18.0"
   category: Rma
-  default_branch: "16.0"
+  default_branch: "18.0"
   name: Odoo for return merchandise authorization (rma)
   psc: logistics-maintainers
   psc_rep: logistics-maintainers-psc-representative