Center images using CSS
Remove tests testing centering
Merge pull request #23 from thomaslindstrom/feature/center-images

Center images using CSS
Remove unneeded active state tracking

These were here previously to trigger re-centering which is now
handled by CSS.

Thanks @thomaslindstrom
Prepare 0.35.0 release
Merge branch 'master' of github.com:atom/image-view into feature/zoom-controls