old_contents: module.exports = {
  	useTabs: true,
  	tabWidth: 4,
  	printWidth: 80,
  	singleQuote: true,
  	trailingComma: 'es5',
  	bracketSpacing: true,
  	parenSpacing: true,
  	jsxBracketSameLine: false,
  	semi: true,
  	arrowParens: 'always',
  };
  
new_contents: module.exports = {
  	useTabs: true,
  	tabWidth: 4,
  	printWidth: 80,
  	singleQuote: true,
  	trailingComma: 'es5',
  	bracketSpacing: true,
  	parenSpacing: true,
  	jsxBracketSameLine: false,
  	semi: true,
  	arrowParens: 'always',
  	endOfLine: 'lf',
  };
  
subject: add `endOfLine` Prettier option `lf`