add test for non string map keys for ron format

Author: Max Christoph

tests/Settings.ron

@@ -18,5 +18,13 @@
     }
   ),
   FOO: "FOO should be overridden",
-  bar: "I am bar"
+  bar: "I am bar",
+    map: {
+        1: '1',
+        2: '4',
+        3: '9',
+        4: '1',
+        5: '2',
+        6: '3',
+    },
 )

tests/file_ron.rs

@@ -1,5 +1,6 @@
 #![cfg(feature = "ron")]
 
+use std::collections::HashMap;
 use serde_derive::Deserialize;
 
 use std::path::PathBuf;
@@ -27,6 +28,7 @@ struct Settings {
     place: Place,
     #[serde(rename = "arr")]
     elements: Vec<String>,
+    map: HashMap<u8, char>,
 }
 
 fn make() -> Config {