refactor: various changes

[nfischer]

• add some tests for ls
• add curly brace rule
• rename eslintrc to have the json extension
• delete some dead code
• ignore coverage for certain lines.

Assigning @levithomason for review, but if he's busy I can review and merge this myself after a few days.

[levithomason]

Didn't pull and manually try it out, but the changes LGTM.