Wildcard route: Use * as the route key to accept any domain.

Use `*` as the route key to accept any domain.

routes.json
```
{
  "*": "localhost:3000",
  "foo.com": "localhost:3001",
  "bar.net": "localhost:3002"
}
```

Returns
```
foo.com:80
  >> localhost:3001

bar.net
  >> localhost:3002

foobar.org
  >> localhost:3000

barfoo.net
  >> localhost:3000
```