This means that if you just have swiftlint installed, it won't be
enabled automatically. You either need a `.swiftlint.yml` or you need to
set `g:syntastic_swift_swiftlint_use_defaults` to 1 in your vimrc.
This allows projects using swift package manager to get inline errors
with syntastic.
You can customize the main executable, or the arguments passed to it,
through global configuration variables.
Unfortunately this really never worked. Since it doesn't know about
multiple files or frameworks the only time this would work is if you had
a single raw swift file. Until this is fixed it isn't worth havin.
