Merge pull request #199 from yuheiy/fix-promise-typing

improve typing for `readdirpPromise`

index.ts

@@ -274,7 +274,7 @@ export const readdirp = (root: Path, options: Partial<ReaddirpOptions> = {}) =>
 };
 
 export const readdirpPromise = (root: Path, options: Partial<ReaddirpOptions> = {}) => {
- return new Promise((resolve, reject) => {
+ return new Promise<Path[]>((resolve, reject) => {
  const files: Path[] = [];
  readdirp(root, options)
  .on('data', (entry) => files.push(entry))