We were very inconsistent regarding these rules.
Personally I prefer no empty lines around blocks, clases, etc... as
recommended by the Ruby style guide [1], and they're the default values
in rubocop, so those are the settings I'm applying.
The exception is the `private` access modifier, since we were leaving
empty lines around it most of the time. That's the default rubocop rule
as well. Personally I don't have a strong preference about this one.
[1] https://rubystyle.guide/#empty-lines-around-bodies
These variables can be considered a block, and so removing them doesn't
make the test much harder to undestand.
Sometimes these variables formed the setup, sometimes they formed an
isolated part of the setup, and sometimes they were the part of the test
that made the test different from other tests.
Now factories define default headings for investments, so there's no
need to create a group and a heading to create an investment.
Likewise, in order to create a heading it isn't necessary to specify a
group anymore; specifying the budget is enough.
It's possible that there are more similar cases we haven't simplified
yet; I'm only addressing the obvious ones.
