Upgrade from futures-preview to futures 0.3.1, and remove futures 0.1 where currently possible (#4083)

* Migrate node and node-template

* Migrate srml

* Simple changes

* Add async-std for interval

* Fix test-runtime warning

* Small changes

* move futures01 in core/rpc to dev-deps

* Change wasm CI builds

* Switch to async-std 1.0.1

* Remove async-std dep of network

* Add modified lockfile

* Fix node cli browser build

* Remove authority-discovery async-std dep

* Add Send + Sync to interval dyn stream

substrate/client/consensus/slots/src/lib.rs

@@ -192,12 +192,10 @@ pub trait SimpleSlotWorker<B: BlockT> {
 				remaining_duration,
 			).map_err(|e| consensus_common::Error::ClientImport(format!("{:?}", e))),
 			Delay::new(remaining_duration)
-				.map_err(consensus_common::Error::FaultyTimer)
 		).map(|v| match v {
 			futures::future::Either::Left((b, _)) => b.map(|b| (b, claim)),
-			futures::future::Either::Right((Ok(_), _)) =>
+			futures::future::Either::Right(_) =>
 				Err(consensus_common::Error::ClientImport("Timeout in the Slots proposer".into())),
-			futures::future::Either::Right((Err(err), _)) => Err(err),
 		});
 
 		let block_import_params_maker = self.block_import_params();

substrate/client/consensus/slots/src/slots.rs

@@ -137,8 +137,7 @@ impl<SC: SlotCompatible + Unpin> Stream for Slots<SC> {
 			if let Some(ref mut inner_delay) = self.inner_delay {
 				match Future::poll(Pin::new(inner_delay), cx) {
 					Poll::Pending => return Poll::Pending,
-					Poll::Ready(Err(err)) => return Poll::Ready(Some(Err(Error::FaultyTimer(err)))),
-					Poll::Ready(Ok(())) => {}
+					Poll::Ready(()) => {}
 				}
 			}