This commit contains a naming refactor for NewNotification to Notification, fixed integration test and a WebSocket test.

Classes:
- FriendshipController: JPA transaction for friendship create, already rejected condition transactional
- Secured: isMember() conditional test transactional
- WebSocketController: Add required return, improve code by using lambda expression
- Notification: Rename this class as the deprecated Notification is not used anymore in the whole system
- Friendship: Affected by naming refactor, code improvement by using lambda expression
- NotificationController, ProfileController, BaseNotifiable, INotifiable, EmailService, NotificationService, Group, GroupAccount, : Affected by naming refactor of Notification
- MockInputWebSocket, MockOutputWebSocket, MockWebSocket: Implement mocks for WebSocket test
- WebSocketTest: Implement WebSocket test
- IntegrationTest: Fix integration test for using real database

Templates:
- All templates are refactored due to the naming refactoring of Notification

Other:
- application.sample.conf: Add default parameters from Play documentation (https://www.playframework.com/documentation/2.0/SettingsJDBC)
- build.sbt: Update dependencies