add: 罗马数字转整数

test/string/roman-to-integer.test.js

@@ -0,0 +1,8 @@
+import { romanToInt } from '../../src/string/roman-to-integer'
+
+test('罗马数字转整数', () => {
+  expect(romanToInt('III')).toBe(3)
+  expect(romanToInt('IV')).toBe(4)
+  expect(romanToInt('IX')).toBe(9)
+  expect(romanToInt('LVIII')).toBe(58)
+})