karma: leaderboard + rank, drop code-noise targets, atomic store writes

src/bot/modules/weather.rs

@@ -132,7 +132,12 @@ impl Store {
     }
 
     fn save(&self, path: &Path) -> io::Result<()> {
-        fs::write(path, to_json(&self.map) + "\n")
+        let body = to_json(&self.map) + "\n";
+        let mut tmp = path.to_path_buf().into_os_string();
+        tmp.push(".tmp");
+        let tmp = PathBuf::from(tmp);
+        fs::write(&tmp, body)?;
+        fs::rename(&tmp, path)
     }
 
     fn get(&self, nick: &str) -> Option<&String> {