Add version flag in executable

Author: kachick

scraper/src/main.rs

@@ -66,6 +66,7 @@ fn main() {
     opts.optflag("t", "text", "output text of elements");
     opts.optflag("h", "help", "this cruft");
     opts.optopt("", "install-man-page", "install real documentation", "PATH");
+    opts.optflag("", "version", "output version number");
 
     let args: Vec<String> = env::args().collect();
     let matches = match opts.parse(&args[1..]) {
@@ -79,6 +80,10 @@ fn main() {
         );
         return;
     }
+    if matches.opt_present("version") {
+        println!("{} {}", env!("CARGO_PKG_NAME"), env!("CARGO_PKG_VERSION"));
+        return;
+    }
 
     if let Some(path) = matches.opt_str("install-man-page") {
         let mut path = PathBuf::from(path);