Stop requiring git hooks to lint

[peterbe]

99% of the time I use Atom. Atom has great "bindings" with Prettier so you can configure it to Prettier format upon file save. That's what the current lint git pre-commit hooks currently.
The advantage with doing it in the IDE is that you see what changes right away.

The other few times (or any other contributor) uses a non-IDE with prettier integration, the lintcheck in travis is there to prevent PRs being made that don't conform.

For those reasons, let's drop the lint-staged script hook.