Update pyo3 to a stable version

Author: konstin

Cargo.toml

@@ -10,12 +10,12 @@ keywords = ["numpy", "python", "binding"]
 license-file = "LICENSE"
 
 [dependencies]
-cfg-if = "0.1.5"
-libc = "0.2"
-num-complex = "0.2"
+cfg-if = "0.1.6"
+libc = "0.2.43"
+num-complex = "0.2.1"
 num-traits = "0.2.6"
-ndarray = "0.12"
-pyo3 = "0.5.0-alpha.2"
+ndarray = "0.12.0"
+pyo3 = "0.5.0"
 
 [features]
 # In default setting, python version is automatically detected