Add macros feature to Tokio, since we use select

Cargo.toml

@@ -28,7 +28,7 @@ http = "1.0"
 http-body-util = "0.1"
 hyper = { version = "1.0", features = ["full"] }
 hyper-util = { version = "0.1", features = ["tokio"] }
-tokio = { version = "1.5.0", features = ["rt"] }
+tokio = { version = "1.5.0", features = ["rt", "macros"] }
 deadpool = "0.9.2"
 async-trait = "0.1"
 once_cell = "1"