input: Write a python function to convert a string date in the format "dd/mm/yyyy" to a datetime object.
  assert convert_to_date("25/12/2020") == datetime.datetime(2020, 12, 25, 0, 0)
  assert convert_to_date("01/01/2021") == datetime.datetime(2021, 1, 1, 0, 0)
  assert convert_to_date("14/07/1789") == datetime.datetime(1789, 7, 14, 0, 0)
output: import datetime
  
  def convert_to_date(date_str):
      return datetime.datetime.strptime(date_str, "%d/%m/%Y")