Update to tokio 1.1 (#2172)

## Issue Addressed

resolves #2129
resolves #2099 
addresses some of #1712
unblocks #2076
unblocks #2153 

## Proposed Changes

- Updates all the dependencies mentioned in #2129, except for web3. They haven't merged their tokio 1.0 update because they are waiting on some dependencies of their own. Since we only use web3 in tests, I think updating it in a separate issue is fine. If they are able to merge soon though, I can update in this PR. 

- Updates `tokio_util` to 0.6.2 and `bytes` to 1.0.1.

- We haven't made a discv5 release since merging tokio 1.0 updates so I'm using a commit rather than release atm. **Edit:** I think we should merge an update of `tokio_util` to 0.6.2 into discv5 before this release because it has panic fixes in `DelayQueue`  --> PR in discv5:  https://github.com/sigp/discv5/pull/58

## Additional Info

tokio 1.0 changes that required some changes in lighthouse:

- `interval.next().await.is_some()` -> `interval.tick().await`
- `sleep` future is now `!Unpin` -> https://github.com/tokio-rs/tokio/issues/3028
- `try_recv` has been temporarily removed from `mpsc` -> https://github.com/tokio-rs/tokio/issues/3350
- stream features have moved to `tokio-stream` and `broadcast::Receiver::into_stream()` has been temporarily removed -> `https://github.com/tokio-rs/tokio/issues/2870
- I've copied over the `BroadcastStream` wrapper from this PR, but can update to use `tokio-stream` once it's merged https://github.com/tokio-rs/tokio/pull/3384

Co-authored-by: realbigsean <seananderson33@gmail.com>

beacon_node/client/Cargo.toml

@@ -26,10 +26,10 @@ error-chain = "0.12.4"
 serde_yaml = "0.8.13"
 slog = { version = "2.5.2", features = ["max_level_trace"] }
 slog-async = "2.5.0"
-tokio = "0.3.2"
+tokio = "1.1.0"
 dirs = "3.0.1"
 futures = "0.3.7"
-reqwest = { version = "0.10.8", features = ["native-tls-vendored"] }
+reqwest = { version = "0.11.0", features = ["native-tls-vendored"] }
 url = "2.1.1"
 eth1 = { path = "../eth1" }
 genesis = { path = "../genesis" }

beacon_node/client/src/notifier.rs

@@ -1,7 +1,6 @@
 use crate::metrics;
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use eth2_libp2p::NetworkGlobals;
-use futures::prelude::*;
 use parking_lot::Mutex;
 use slog::{debug, error, info, warn, Logger};
 use slot_clock::SlotClock;
@@ -64,26 +63,32 @@ pub fn spawn_notifier<T: BeaconChainTypes>(
         }
 
         // Perform post-genesis logging.
-        while interval.next().await.is_some() {
+        loop {
+            interval.tick().await;
             let connected_peer_count = network.connected_peers();
             let sync_state = network.sync_state();
 
-            let head_info = beacon_chain.head_info().map_err(|e| {
-                error!(
-                    log,
-                    "Failed to get beacon chain head info";
-                    "error" => format!("{:?}", e)
-                )
-            })?;
+            let head_info = match beacon_chain.head_info() {
+                Ok(head_info) => head_info,
+                Err(e) => {
+                    error!(log, "Failed to get beacon chain head info"; "error" => format!("{:?}", e));
+                    break;
+                }
+            };
 
             let head_slot = head_info.slot;
-            let current_slot = beacon_chain.slot().map_err(|e| {
-                error!(
-                    log,
-                    "Unable to read current slot";
-                    "error" => format!("{:?}", e)
-                )
-            })?;
+            let current_slot = match beacon_chain.slot() {
+                Ok(slot) => slot,
+                Err(e) => {
+                    error!(
+                        log,
+                        "Unable to read current slot";
+                        "error" => format!("{:?}", e)
+                    );
+                    break;
+                }
+            };
+
             let current_epoch = current_slot.epoch(T::EthSpec::slots_per_epoch());
             let finalized_epoch = head_info.finalized_checkpoint.epoch;
             let finalized_root = head_info.finalized_checkpoint.root;
@@ -175,11 +180,10 @@ pub fn spawn_notifier<T: BeaconChainTypes>(
 
             eth1_logging(&beacon_chain, &log);
         }
-        Ok::<(), ()>(())
     };
 
     // run the notifier on the current executor
-    executor.spawn(interval_future.unwrap_or_else(|_| ()), "notifier");
+    executor.spawn(interval_future, "notifier");
 
     Ok(())
 }