feat: Add a impl From<http::HeaderName> for Vary (#210)

Author: CosmicHorrorDev

src/common/vary.rs

@@ -1,4 +1,4 @@
-use http::HeaderValue;
+use http::{HeaderName, HeaderValue};
 
 use crate::util::FlatCsv;
 
@@ -53,6 +53,12 @@ impl Vary {
     }
 }
 
+impl From<HeaderName> for Vary {
+    fn from(name: HeaderName) -> Self {
+        Vary(HeaderValue::from(name).into())
+    }
+}
+
 /*
 test_vary {
     test_header!(test1, vec![b"accept-encoding, accept-language"]);