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>

testing/simulator/Cargo.toml

@@ -13,9 +13,8 @@ types = { path = "../../consensus/types" }
 validator_client = { path = "../../validator_client" }
 parking_lot = "0.11.0"
 futures = "0.3.7"
-tokio = "0.3.2"
+tokio = "1.1.0"
 eth1_test_rig = { path = "../eth1_test_rig" }
 env_logger = "0.8.2"
 clap = "2.33.3"
 rayon = "1.4.1"
-tokio-compat-02 = "0.1"

testing/simulator/src/eth1_sim.rs

@@ -90,7 +90,8 @@ pub fn run_eth1_sim(matches: &ArgMatches) -> Result<(), String> {
         // Start a timer that produces eth1 blocks on an interval.
         tokio::spawn(async move {
             let mut interval = tokio::time::interval(eth1_block_time);
-            while interval.next().await.is_some() {
+            loop {
+                interval.tick().await;
                 let _ = ganache.evm_mine().await;
             }
         });
@@ -219,9 +220,7 @@ pub fn run_eth1_sim(matches: &ArgMatches) -> Result<(), String> {
         Ok::<(), String>(())
     };
 
-    env.runtime()
-        .block_on(tokio_compat_02::FutureExt::compat(main_future))
-        .unwrap();
+    env.runtime().block_on(main_future).unwrap();
 
     env.fire_signal();
     env.shutdown_on_idle();

testing/simulator/src/no_eth1_sim.rs

@@ -158,9 +158,7 @@ pub fn run_no_eth1_sim(matches: &ArgMatches) -> Result<(), String> {
         Ok::<(), String>(())
     };
 
-    env.runtime()
-        .block_on(tokio_compat_02::FutureExt::compat(main_future))
-        .unwrap();
+    env.runtime().block_on(main_future).unwrap();
 
     env.fire_signal();
     env.shutdown_on_idle();

testing/simulator/src/sync_sim.rs

@@ -130,9 +130,7 @@ fn syncing_sim(
         Ok::<(), String>(())
     };
 
-    env.runtime()
-        .block_on(tokio_compat_02::FutureExt::compat(main_future))
-        .unwrap();
+    env.runtime().block_on(main_future).unwrap();
 
     env.fire_signal();
     env.shutdown_on_idle();
@@ -217,7 +215,8 @@ pub async fn verify_one_node_sync<E: EthSpec>(
     // limited to at most `sync_timeout` epochs
     let mut interval = tokio::time::interval(epoch_duration);
     let mut count = 0;
-    while interval.next().await.is_some() {
+    loop {
+        interval.tick().await;
         if count >= sync_timeout || !check_still_syncing(&network_c).await? {
             break;
         }
@@ -254,7 +253,8 @@ pub async fn verify_two_nodes_sync<E: EthSpec>(
     // limited to at most `sync_timeout` epochs
     let mut interval = tokio::time::interval(epoch_duration);
     let mut count = 0;
-    while interval.next().await.is_some() {
+    loop {
+        interval.tick().await;
         if count >= sync_timeout || !check_still_syncing(&network_c).await? {
             break;
         }
@@ -302,7 +302,8 @@ pub async fn verify_in_between_sync<E: EthSpec>(
     // limited to at most `sync_timeout` epochs
     let mut interval = tokio::time::interval(epoch_duration);
     let mut count = 0;
-    while interval.next().await.is_some() {
+    loop {
+        interval.tick().await;
         if count >= sync_timeout || !check_still_syncing(&network_c).await? {
             break;
         }