Cache Bundler to S3 on Travis
maybe the latest Bundler isn't needed anymore?
Cache the test app to S3 on Travis
turns out tar remembers the folder structure!
create proper URLs
actually save files when `:as` isn't provided
update `rake setup` to not run if test app exists
record SHA changes in the console output
alphabetically sort files to be checked
Merge pull request #3095

Conflicts:
	.travis.yml