Fixes validate html to allow using multiple h1 tags
Update dependencies.
Update Jekyll to v2.0.0.
Run `grunt`.
Update grunt-csscomb.
Update dependencies.
Update dependencies.
Update dependencies and Jekyll version.
Remove `layout: nil`.

It throws a warning with the latest Jekyll.
Merge pull request #608 from watilde/fixes-validate-html

Fixes validate html to allow using multiple h1 tags
Fixes conflict