Having two questions, each of them with two comments, made the code hard
to follow.
Grouping the comments inside the block creating the questions makes it
easier to know which comment belongs to which question, even if the code
is still not 100% readable.
We also remove instance variables, which by the way used the same
variable name for two different things.
These factories were only used in one place and they even declared ID
attributes. Using the comment factory with the `commentable` attribute
does the same thing.
The `type: :feature` is automatically detected by RSpec because these
tests are inside the `spec/features` folder. Using `feature` re-adds a
`type: :feature` to these files, which will result in a conflict when we
upgrade to Rails 5.1's system tests.
Because of this change, we also need to change `background` to `before`
or else these tests will fail.
We're also adding a rubocop rule so we dont' accidentally add these
keywords again.