Fix for multiple linter regression

https://github.com/AtomLinter/Linter/issues/193
It was returning after one linter was applied.
Merge pull request #194 from mdgriffith/patch-3

Fix for multiple linter regression
Better fix for #193, including regression test

This fix is better because it achieves what I was originally trying to do with
that `return` statement - stop CoffeeScript from accumalting the implicit
returns for the `for` loop into an array.

Test Plan:
Ran new test before and after fix. It works!
:memo: update changelog
Prepare 0.5.17 release