Add `.css` ext to imports for interoperability
1.7.1
Fix test reference to index.css

I was trying to make a PR a got an issue about that index.css reference. This fix works for me & seems logical.
Fix dynamic aspect ratio support

Moving the responsibility for the correct aspect ratio to a
pseudo-element broke the ability to dynamically set the ratio via inline
styles. This change uses an empty element rather than a pseudo-element.

It also removes the assumption that an image or embed (e.g., iframe)
will be a child of the component. This makes it more flexible and a more
well-behaved component.
Update preprocessor
2.0.0
2.0.1
Merge branch 'master' into gh-pages
Commit build