Add support for simple 301 redirects through config file
Invalidate redirects in CloudFront
Documentation for simple redirects
Extract method for the sake of readability
Refactor redirects implementation

- make #setup_redirects return paths of succeeded operations
- add "Creating new redirects ..." stdout
Add example of setting two redirects
Add example of redirect path/item.ext
Add example of using created-redirects count
Remove case `unless s3.write`

The s3#write method seems never to return anything that evaluates to
false.
Bump version to 2.8.0
Merge branch 'redirects'