Vendor dependencies for 0.3.0 release

vendor/tracing/tests/no_subscriber.rs

@@ -0,0 +1,16 @@
+#![cfg(feature = "std")]
+
+use tracing_mock::subscriber;
+
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
+#[test]
+fn no_subscriber_disables_global() {
+    // Reproduces https://github.com/tokio-rs/tracing/issues/1999
+    let (subscriber, handle) = subscriber::mock().only().run_with_handle();
+    tracing::subscriber::set_global_default(subscriber)
+        .expect("setting global default must succeed");
+    tracing::subscriber::with_default(tracing::subscriber::NoSubscriber::default(), || {
+        tracing::info!("this should not be recorded");
+    });
+    handle.assert_finished();
+}