Vendor dependencies

Let's see how I like this workflow.

vendor/tokio-stream/tests/time_throttle.rs

@@ -0,0 +1,28 @@
+#![warn(rust_2018_idioms)]
+#![cfg(all(feature = "time", feature = "sync", feature = "io-util"))]
+
+use tokio::time;
+use tokio_stream::StreamExt;
+use tokio_test::*;
+
+use std::time::Duration;
+
+#[tokio::test]
+async fn usage() {
+    time::pause();
+
+    let mut stream = task::spawn(futures::stream::repeat(()).throttle(Duration::from_millis(100)));
+
+    assert_ready!(stream.poll_next());
+    assert_pending!(stream.poll_next());
+
+    time::advance(Duration::from_millis(90)).await;
+
+    assert_pending!(stream.poll_next());
+
+    time::advance(Duration::from_millis(101)).await;
+
+    assert!(stream.is_woken());
+
+    assert_ready!(stream.poll_next());
+}