Adjust rules for comments

[jamescooke]

# comments are helpful in complicated tests but they can be disruptive to test structure. This is my current thinking:

• Arrange: # comments allowed throughout.
• Act: No # comments allowed - if something is important enough to comment in the Act block, then it should go in the docstring of the test itself.
• Arrange: # comments allowed throughout.

Good examples that need to be edited:

• flake8-aaa/examples/good/test_comments_aaa05.py

  Lines 14 to 27 in de688e5

  	def test_act():
  	nothing = None
  	with pytest.raises(AttributeError):
  	# You can't get something from nothing
  	nothing.get_something()
  	def test_assert():
  	result = list()
  	assert not result
  	# A copy of nothing is nothing
  	assert result.copy() == []

• flake8-aaa/examples/good/test_comments.py

  Lines 4 to 21 in de688e5

  	def test_comment_before_act():
  	x = 1
  	y = 2
  	# Sum x and y
  	result = x + y
  	assert result == 2
  	def test_comment_after_act():
  	x = 1
  	y = 2
  	result = x + y
  	# Sum x and y
  	assert result == 2