whole_func_string: function deleteBackup(config) {
  
  	return new Promise((resolve, reject) => {
  
  		const backupPath = path.join(process.cwd(), (config.backup !== undefined) ? config.backup : ".backup");
  
  		fs.remove(backupPath, (error) => {
  
  			(error === null) ? resolve(config) : reject(error);
  
  		});
  
  	});
  
  }
func_code_string: function deleteBackup(config) {
  
  	return new Promise((resolve, reject) => {
  
  		const backupPath = path.join(process.cwd(), (config.backup !== undefined) ? config.backup : ".backup");
  
  		fs.remove(backupPath, (error) => {
  
  			(error === null) ? resolve(config) : reject(error);
  
  		});
  
  	});
  
  }
func_documentation_string: Deletes the backup directory.
  
  @param {Object} config - A configuration.
  @return {Promise} A promise that returns the given configuration.