added missing save method impl

fyrox-animation/src/lib.rs

@@ -122,8 +122,10 @@ impl Visit for AnimationTracksData {
 }
 
 impl ResourceData for AnimationTracksData {
-    fn save(&mut self, _path: &Path) -> Result<(), Box<dyn Error>> {
-        // TODO
+    fn save(&mut self, path: &Path) -> Result<(), Box<dyn Error>> {
+        let mut visitor = Visitor::new();
+        self.visit("Tracks", &mut visitor)?;
+        visitor.save_ascii_to_file(path)?;
         Ok(())
     }