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
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.
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.
