Revert "trying to add user add controller (to test if jpa does work at least with adding a user table which is much simpler than bill)"

This reverts commit 1f66d3c76974de65eca58acc90c7fffa8edf3110.
got addUser method to show up as a REST path without the http post body info yet.
committing before updating pom to remove unused deps
fixed the URL mapping issues. But addBill() persist fix still in the works. The reason it fails is because of dependencies of child table values that depend upon billId. But billId gets populated by the datbase when the bill table is inserted. Somehow this value needs to be automatically (or manually if it's not possible to do so automatically) into the billId values of these child tables.