fix(rename): shortened of #<File> has only a getter
Gulp use a new File object to ease pain of computing shortened names. The shortened is not settable. So I'm using the path instead.
See https://github.com/wearefractal/gulp/blob/dcaa92b965346c459b684e65779683bb006e9c8f/CHANGELOG.md#27
fix(test): tricky hello.min.txt works