Make :status in requests be a stream error

tests/h2-support/src/frames.rs

@@ -2,7 +2,7 @@ use std::convert::TryInto;
 use std::fmt;
 
 use bytes::Bytes;
-use http::{self, HeaderMap};
+use http::{self, HeaderMap, StatusCode};
 
 use h2::frame::{self, Frame, StreamId};
 
@@ -162,6 +162,14 @@ impl Mock<frame::Headers> {
         Mock(frame)
     }
 
+    pub fn status(self, value: StatusCode) -> Self {
+        let (id, mut pseudo, fields) = self.into_parts();
+
+        pseudo.set_status(value);
+
+        Mock(frame::Headers::new(id, pseudo, fields))
+    }
+
     pub fn scheme(self, value: &str) -> Self {
         let (id, mut pseudo, fields) = self.into_parts();
         let value = value.parse().unwrap();