chore: checkpoint before Python removal

vendor/futures/tests/compat.rs

@@ -0,0 +1,16 @@
+#![cfg(feature = "compat")]
+#![cfg(not(miri))] // Miri does not support epoll
+
+use futures::compat::Future01CompatExt;
+use futures::prelude::*;
+use std::time::Instant;
+use tokio::runtime::Runtime;
+use tokio::timer::Delay;
+
+#[test]
+fn can_use_01_futures_in_a_03_future_running_on_a_01_executor() {
+    let f = async { Delay::new(Instant::now()).compat().await };
+
+    let mut runtime = Runtime::new().unwrap();
+    runtime.block_on(f.boxed().compat()).unwrap();
+}