code: function tryFile(file) {
  	return new Promise((resolve, reject) => {
  		fs.stat(file, (err, stat) => {
  			if (err) {
  				return reject(err);
  			}
  
  			if (!stat.isFile()) {
  				return reject(new Error(`${file} is not a file`));
  			}
  
  			resolve(file);
  		});
  	});
  }
docs: Check if given file exists and it’s a file, not directory
  @param  {String} file
  @return {Promise}