ETag middleware for Actix web

To use ```rust use actixweb::{web, App, HttpServer, HttpResponse, Error}; use actixmiddleware_etag::{Etag};

[actix_web::main]

async fn main() -> std::io::Result<()> { HttpServer::new(move || App::new() // Add etag headers to your actix application. Calculating the hash of your GET bodies and putting the base64 hash in the ETag header .wrap(Etag::default()) ... .bind(("127.0.0.1", 8080))? .run() .await } ```

This will hash all bodies for GET requests and base64 encode the hash as a weak ETag header in the response