use minitest
use bundler instead of jeweler
add retina modifier to url

file_50x50@2x.jpg will return a 100x100 pixel image
back to old version number
remove unused to_path method
Use markdown for readme
add Travis-CI integration
better description in gemspec
ruby syntax highlighting in readme
Make file extension optional. Closes: c842688
output
Revert "output"

This reverts commit e49871328f3f39be2d07f475c0d40350ef1c13f3.
Extract constructing Mapel command from #render_thumbnail
simplify tests
rename run_command to transform_image and add preserve_metadata option (defaults to true)
simpler serve method
more test helpers
small fix
another small fix
gemspecs