fixed zip filetype

src/main.rs

@@ -95,6 +95,7 @@ fn get_mime_type<'a>(extension: Option<&'a OsStr>) -> String {
         Some("html") => "text/html".to_string(),
         Some("png") => "image/png".to_string(),
         Some("ico") => "image/vnd.microsoft.icon".to_string(),
+        Some("zip") => "application/zip, application/octet-stream".to_string(),
         _ => "text/text".to_string(),
     }
 }