feat: change default async runtime to tokio

Signed-off-by: hackerchai <i@hackerchai.com>

Cargo.toml

@@ -36,11 +36,11 @@ slog        = { version = "2.7.0", optional = true }
 slog-async  = { version = "2.6.0", optional = true }
 slog-term   = { version = "2.8.0", optional = true }
 thiserror   = "1.0.24"
-tokio       = { version = "1.4.0", optional = true, default-features = false }
+tokio       = { version = "1.5.0", optional = true, default-features = false }
 tokio-stream = { version = "0.1", optional = true, default-features = false }
 
 [features]
-default = ["runtime-async-std", "incremental"]
+default = ["runtime-tokio", "incremental"]
 
 cached            = ["lru"]
 explain           = []
@@ -59,7 +59,7 @@ serde     = { version = "1.0.125", features = ["derive"] }
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
 async-std = { version = "1.9.0", features = ["attributes"] }
 serde     = { version = "1.0.125", features = ["derive"] }
-tokio     = { version = "1.4.0", features = ["full"] }
+tokio     = { version = "1.5.0", features = ["full"] }
 
 [profile.release]
 codegen-units = 1