input: Write a python function to increase the salary of an Employee by a given percentage.
  assert increase_salary(Employee('John', 'Software Engineer', 6000), 10).salary == 6600
  assert increase_salary(Employee('Jane', 'Data Scientist', 7000), 20).salary == 8400
  assert increase_salary(Employee('Alice', 'Manager', 8000), 5).salary == 8400
output: def increase_salary(employee, percentage):
      employee.salary += employee.salary * (percentage / 100)
      return employee