input: Write a python function to check if a value exists in a list.
  assert check_value([2, 3, 7, 8], 7) == True
  assert check_value([1, 2, 3, 4, 5], 6) == False
  assert check_value([10, 20, 30, 40], 30) == True
output: def check_value(lst, value):
      return value in lst