Fix tokio deprecation warnings (#358)

* Fix thread_pool::Builder deprecation

* Fix reactor::Handle::current() deprecaction warning

Author: ascjones

http/src/lib.rs

@@ -459,7 +459,7 @@ fn serve<M: jsonrpc::Metadata, S: jsonrpc::Middleware<M>>(
 ) {
 	let (shutdown_signal, local_addr_tx) = signals;
 	executor.spawn(future::lazy(move || {
-		let handle = tokio::reactor::Handle::current();
+		let handle = tokio::reactor::Handle::default();
 
 		let bind = move || {
 			let listener = match addr {

server-utils/src/reactor.rs

@@ -107,20 +107,15 @@ impl RpcEventLoop {
 		}
 
 		let handle = tb.spawn(move || {
-			let mut tp_builder = tokio::executor::thread_pool::Builder::new();
-
-			let pool_size = match num_cpus::get_physical() {
+			let core_threads = match num_cpus::get_physical() {
 				1 => 1,
 				2...4 => 2,
 				_ => 3,
 			};
 
-			tp_builder
-				.pool_size(pool_size)
-				.name_prefix("jsonrpc-eventloop-");
-
 			let runtime = tokio::runtime::Builder::new()
-				.threadpool_builder(tp_builder)
+				.core_threads(core_threads)
+				.name_prefix("jsonrpc-eventloop-")
 				.build();
 
 			match runtime {