support deleting/editing loyalty transactions

Changed the routing to use the actual object name (loyalty point
tranasaction) in the admin. as its just the admin, removing the extra
_transaction isn't worth the complications in the spree resource
controller

Change-Id: I5b77ec69f2c1ab91c3000ed720daa11804b7c135
Merge pull request #1 from freerunningtech/loyalty_point_admin

support deleting/editing loyalty transactions