title: Create Primary Key other than Id in Jhipster Entity
body: <p>I want to create two entities.</p>
  
  <p>Departments(Department Id,Department Name) and 
  Employees(Employee Id, Employee Name, Address).</p>
  
  <p>I want these primary keys for the tables:</p>
  
  <p>Department Id for Departments,
  Employee Id for Employees.</p>
  
  <p>And Jhipster creates two tables as:
  Departments(Id, Department Id, Department Name) and 
  Empployee(Id, Employee Id, Employee Name, Address)</p>
  
  <p>and it takes Id as a primary key in both of these tables.</p>
  
  <p>In my Database Design I want Department Id and Employee Id as a primary key. So what to do next? </p>