Upgrade discovery and restructure task execution (#1693)

* Initial rebase

* Remove old code

* Correct release tests

* Rebase commit

* Remove eth2-testnet dep on eth2libp2p

* Remove crates lost in rebase

* Remove unused dep

beacon_node/websocket_server/Cargo.toml

@@ -10,9 +10,8 @@ edition = "2018"
 futures = "0.3.5"
 serde = "1.0.110"
 serde_derive = "1.0.110"
-serde_json = "1.0.52"
 slog = "2.5.2"
 tokio = { version = "0.2.22", features = ["full"] }
 types = { path = "../../consensus/types" }
 ws = "0.9.1"
-environment = { path = "../../lighthouse/environment" }
+task_executor = { path = "../../common/task_executor" }

beacon_node/websocket_server/src/lib.rs

@@ -34,7 +34,7 @@ impl<T: EthSpec> WebSocketSender<T> {
 }
 
 pub fn start_server<T: EthSpec>(
-    executor: environment::TaskExecutor,
+    executor: task_executor::TaskExecutor,
     config: &Config,
 ) -> Result<(WebSocketSender<T>, SocketAddr), String> {
     let log = executor.log();