finzdata 0.2.0

//! Point-in-time dealer gamma for SPY: cargo run --example gex
#[tokio::main]
async fn main() -> finzdata::Result<()> {
    let fz = finzdata::Client::new()?;
    let gex = fz.gex("SPY", Some("2025-01-01"), None).await?;
    for d in gex.data.iter().rev().take(5) {
        println!("{} spot {:?} net {:?}bn flip {:?} call wall {:?} put wall {:?}",
                 d.date, d.spot, d.net_gex_bn, d.flip, d.call_wall, d.put_wall);
    }
    Ok(())
}