Reexport features wasm-bindgen/stdweb of parking_lot

parking_lot calls `std::time::Instant::now()` which is not supported on the target `wasm32-unknown-unknown`, and for me caused the runtime error

`Uncaught TypeError: Failed to resolve module specifier "env". Relative references must start with either "/", "./", or "../".
`

Using the parking_lot crate with feature `wasm-bindgen` fixes this.

I assume the same thing would apply to the `stdweb` feature, but I did not test this.