@Override
    public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
      if (exc == null) {
        Files.delete(dir);
        return FileVisitResult.CONTINUE;
      }
      // directory iteration failed, propagate exception
      throw exc;
    }
Test what happens if tagInfoFile does not contain a path, i.e. the value is simply
"image_info.json".
src/test/java/com/spotify/docker/BuildMojoTest.java