input: Write a python function to test log files for positive and negative outcomes.
  assert test_positive('test1.log') == True
  assert test_negative('test2.log') == False
output: def test_positive(log_file):
      with open(log_file, 'r') as file:
          for line in file:
              if 'positive outcome' in line:
                  return True
      return False
  
  def test_negative(log_file):
      with open(log_file, 'r') as file:
          for line in file:
              if 'negative outcome' in line:
                  return True
      return False