Getting 404 Issue when trying to access my route
My `auth.js`

```
const router = require('koa-router')(),
      passport = require('koa-passport'),
      Strategy = require('passport-facebook').Strategy;

passport.serializeUser(function(user, cb) {
  cb(null, user);
});

passport.deserializeUser(function(obj, cb) {
  cb(null, obj);
});

passport.use(new Strategy({
  clientID: process.env.CLIENT_ID,
  clientSecret: process.env.CLIENT_SECRET,
  callbackURL: 'http://localhost:3000/auth/return'
}, function(token, tokenSecret, profile, done) {
  console.log("ACCESS TOKEN: ", accessToken);
  console.log("REFRESH TOKEN: ", refreshToken);
  console.log("PROFILE : ", profile);
  return cb(null, profile);
}));


router.get('/login', passport.authenticate('facebook'));

router.get('/return', passport.authenticate('facebook', { failureRedirect: '/' }), async function returnCallback(ctx, next) {
  await ctx.redirect("/");
});


module.exports = router;
```

My app.js

```
const Koa = require('koa');
const app = new Koa();
const router = require('koa-router')();
const views = require('koa-views');
const co = require('co');
const convert = require('koa-convert');
const json = require('koa-json');
const onerror = require('koa-onerror');
const bodyparser = require('koa-bodyparser')();
const logger = require('koa-logger');
const session = require('koa-session');
const passport = require('koa-passport');

const home = require('./routes/home');
const auth = require('./routes/auth');

// middlewares
app.keys = ['pgn4qn4np89qgn9p4n9p4qn98pq4n98pqn9438n98g34n98q3n9q3g94'];
app.use(convert(bodyparser));
app.use(convert(json()));
app.use(convert(session(app)));
app.use(passport.initialize());
app.use(passport.session());
app.use(convert(logger()));
app.use(require('koa-static')(__dirname + '/public'));

app.use(views(__dirname + '/views', {
  extension: 'ejs'
}));

// logger
app.use(async (ctx, next) => {
  const start = new Date();
  await next();
  const ms = new Date() - start;
  console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
});

router.use('/', home.routes(), home.allowedMethods());
router.use('/auth', auth.routes(), auth.allowedMethods());

app.use(router.routes(), router.allowedMethods());
// response

app.on('error', function(err, ctx){
  console.log(err)
  logger.error('server error', err, ctx);
});


module.exports = app;
```

But when I go to http://localhost:3000/auth/login I just get a 404 error, but if I remove the `passport.authenticate()` and put in a view render instead the route works just fine, so for some reason the `passport-authenticate` is giving me a 404 error. Thanks.
