add proxy authorization

tests/proxy.rs

@@ -1,5 +1,7 @@
 extern crate reqwest;
 
+use reqwest::header::Bearer;
+
 #[macro_use]
 mod support;
 
@@ -12,6 +14,7 @@ fn test_http_proxy() {
             User-Agent: $USERAGENT\r\n\
             Accept: */*\r\n\
             Accept-Encoding: gzip\r\n\
+            Authorization: Bearer MY_SECRET_TOKEN\r\n\
             \r\n\
             ",
         response: b"\
@@ -23,7 +26,8 @@ fn test_http_proxy() {
     };
 
     let proxy_uri = format!("http://{}", server.addr());
-    let proxy = reqwest::Proxy::http(&proxy_uri).unwrap();
+    let mut proxy = reqwest::Proxy::http(&proxy_uri).unwrap();
+    proxy.set_authorization(Bearer { token: "MY_SECRET_TOKEN".to_string() });
 
     let url = "http://hyper.rs/prox";
     let res = reqwest::Client::builder()