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
Assigning a variable to each budget we declare results in useless
assignments. We could just delete the three useless assignments and
leave the fourth one, but I find the code easier to read if we use the
name of the budgets to differenciate between them. This way we also keep
the code vertically aligned.
