use hegel's state machine for PBT

See discussion in hegeldev/hegel-rust#148.

Author: sunshowers

Cargo.lock

@@ -26,7 +26,7 @@ tokio = { version = "1.0.0", features = ["io-std"], optional = true }
 anyhow = "1.0.70"
 dummy-waker = "1.1.0"
 futures = "0.3.25"
-hegeltest = "0.3.4"
+hegeltest = "0.3.7"
 tokio = { version = "1.0.0", features = ["io-std", "io-util", "macros", "rt"] }
 
 [features]