message: Sends modified headers to preview
diff: +use std::collections::HashMap;
  use std::net::{SocketAddr, ToSocketAddrs};
  use chrono::prelude::*;
  use hyper2::client::{HttpConnector, ResponseFuture};
  -use hyper2::header::{HeaderValue, HeaderName};
  +use hyper2::header::{HeaderValue, HeaderName, HeaderMap};
  use hyper2::service::{make_service_fn, service_fn};
  use hyper2::{Body, Client, Request, Uri, Server};
  @@ -151,6 +152,17 @@ fn preview_request(
  let now: DateTime<Local> = Local::now();
  let preview_id = &preview_id;
  + let mut headers: HeaderMap = HeaderMap::new();
  +
  + for header in &parts.headers {
  + let (name, value) = header;
  + let forward_header = format!("cf-ew-raw-{}", name);
  + // TODO: remove unwrap
  + let header_name = HeaderName::from_bytes(forward_header.as_bytes()).unwrap();
  + headers.insert(header_name, value.clone());
  + }
  + parts.headers = headers;
  +
  // TODO: remove unwrap
  parts.uri = get_preview_url(&path).unwrap();
  parts.headers.insert(
  @@ -162,8 +174,8 @@ fn preview_request(
  parts.headers
  .insert(HeaderName::from_static("cf-ew-preview"), HeaderValue::from_str(preview_id).unwrap());
  - let req = Request::from_parts(parts, body);
  + let req = Request::from_parts(parts, body);
  println!(
  "[{}] \"{} {}{} {:?}\"",
  