about_strings.py: Second assertion in test_if_a_string_contains_another_string passes without user intervention

[pavemina]

is_dog_in is expected to evaluate to False, and since __ is defined as False at the top of the file, the second assertion in the test passes without the student having to change __ to False. (this assumes that the first assertion in the test has already been fixed)

python-koans/koans/about_strings.py

Lines 89 to 98 in 30d866a

	def test_if_a_string_contains_another_string(self):
	string = "Pears, lettuce and tomato"
	is_lettuce_in = "lettuce" in string
	assert is_lettuce_in == __
	is_dog_in = "dog" in string
	assert is_dog_in == __