upgrade flow-bin and express flow defs

[magicmark]

Before

markl on macbook in ~/apps/tweenz on git:master ✗ is 📦 v3.0.1-alpha.3
$ node_modules/.bin/flow status
Error ┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈ src/index.js:17:58

Cannot use Middleware [1] without 0-2 type arguments.

     src/index.js
      14│     $Response,
      15│ ) => Promise<void>;
      16│
      17│ export default function tweenz(...tweens: Array<Tween>): Middleware {
      18│     return (req: $Request, res: $Response, next: NextFunction) => {
      19│         // we'll store all chunks passed to res.write/end in memory here
      20│         const bufferList = new BufferList();

     flow-typed/npm/express_v4.x.x.js
 [1] 246│   declare export type Middleware<
     247│     Req: express$Request = express$Request,
     248│     Res: express$Response = express$Response,
     249│   > = express$Middleware<Req, Res>;

Found 1 error

After

It works!

---

I'm going to bump this to v1.0.0 after this, I think we're fairly stable now :)