feat/create-entities

• User
  • id: Long
  • firstName: String
  • lastName: String
  • email: String
  • password: String (Hashé)
  • role: RoleEnum
• Manager extends User
  • role: RoleEnum= ‘MANAGER’
  • List attachedEmployees
• Employee extends User
  • role: RoleEnum = ‘EMPLOYEE’
• Admin extends User
  • role: RoleEnum = ‘ADMIN’