Changed pyo3 to my fork

Author: Andrew J Westlake

Cargo.toml

@@ -15,5 +15,5 @@ harness = false
 futures = "0.3"
 lazy_static = "1.4"
 once_cell = "1.5"
-pyo3 = { version = "0.12" }
+pyo3 = { git = "https://github.com/awestlake87/pyo3", branch = "finalization-bugfix" }
 tokio = { version = "0.3", features = ["full"] }