Fix warnings

validator_client/src/http_api/tests.rs

@@ -34,7 +34,6 @@ use std::time::Duration;
 use task_executor::test_utils::TestRuntime;
 use tempfile::{tempdir, TempDir};
 use tokio::runtime::Runtime;
-use tokio::sync::oneshot;
 use types::graffiti::GraffitiString;
 
 const PASSWORD_BYTES: &[u8] = &[42, 50, 37];
@@ -52,16 +51,6 @@ struct ApiTester {
     _test_runtime: TestRuntime,
 }
 
-// Builds a runtime to be used in the testing configuration.
-fn build_runtime() -> Arc<Runtime> {
-    Arc::new(
-        tokio::runtime::Builder::new_multi_thread()
-            .enable_all()
-            .build()
-            .expect("Should be able to build a testing runtime"),
-    )
-}
-
 impl ApiTester {
     pub async fn new() -> Self {
         let log = test_logger();