updates/ fixes

data/demo.mv.db

src/main/java/com/quackr/demo/user/User.java

src/main/java/com/quackr/demo/user/UserController.java

src/main/java/com/quackr/demo/user/UserRepository.java

src/main/java/com/quackr/demo/user/UserService.java

src/main/resources/application.properties