Add oauth2 client

examples/client.rs

@@ -0,0 +1,11 @@
+// Copyright (c) Tribufu. All Rights Reserved
+
+use tribufu::*;
+
+#[tokio::main]
+async fn main() {
+    match TribufuClient::new(0, "client_secret") {
+        Ok(client) => println!("client_id: {}", client.id()),
+        Err(e) => println!("error: {:?}", e),
+    }
+}