typeable-promisify

- Wrap any node-style callback function with a promise.
- Allows you to specify your own type annotations.
- Strongly typed.

``js
// @flow
import promisify from 'typeable-promisify';

let writeFileAsync = (filePath: string, fileContents: string): Promise => {
return promisify(cb => writeFile(filePath, fileContents, cb));
};

writeFileAsync('fileName', 'fileContents').then(() => {});
``