Start verification at most recently modified file

src/main.rs

@@ -52,7 +52,7 @@ fn main() {
     }
 
     if matches.subcommand_matches("verify").is_some() {
-        match verify() {
+        match verify(None) {
             Ok(_) => {}
             Err(_) => std::process::exit(1),
         }
@@ -81,14 +81,14 @@ fn watch() -> notify::Result<()> {
     let mut watcher: RecommendedWatcher = Watcher::new(tx, Duration::from_secs(2))?;
     watcher.watch("./exercises", RecursiveMode::Recursive)?;
 
-    let _ignored = verify();
+    let _ignored = verify(None);
 
     loop {
         match rx.recv() {
             Ok(event) => match event {
                 DebouncedEvent::Create(b) | DebouncedEvent::Chmod(b) | DebouncedEvent::Write(b) => {
                     if b.extension() == Some(OsStr::new("rs")) {
-                        let _ignored = verify();
+                        let _ignored = verify(Some(b.as_path().to_str().unwrap()));
                     }
                 }
                 _ => {}