code: function(dir) {
          var archivePath = this.readConfig('archivePath');
          var archiveName = this.readConfig('archiveName');
          var containingDirectory = path.dirname(dir);
          var target = path.basename(dir);
  
          var fileName = path.join(archivePath, archiveName);
  
          this.log('saving tarball of ' + dir + ' to ' + fileName);
  
          return tar.c({
            gzip: true,
            file: fileName,
            C: containingDirectory
          }, [target]);
        }
docs: create tarball