De/serialize structs with named fields as array of values.
See: https://github.com/dtolnay/request-for-implementation/issues/3
```rust
use serde_tuple::*;
pub struct Foo<'a> {
}
let foo = Foo { bar: "Yes", baz: 22 };
let json = serde_json::to_string(&foo).unwrap();
println!("{}", &json);
// # => ["Yes",22]
```
License: MIT