message: add falsy types to classNames args types
diff: import { ObjectClassNames } from '../types/props';
  -export default function classNames(...classnames: Array<number | string | ObjectClassNames>) {
  +export default function classNames(...classnames: Array<number | string | ObjectClassNames | false | null | undefined>) {
  let result: string[] = [];
  classnames.forEach((item: number | string | ObjectClassNames): void => {
  