Update README.md

Author: OpenByteDev

README.md

@@ -16,7 +16,7 @@ This is a Rust implementation of the [Pancake Stack](https://esolangs.org/wiki/P
 To use pancakestack, first include this in your Cargo.toml:
 ```toml
 [dependencies]
-"pancakestack" = "0.4"
+"pancakestack" = "0.5"
 ```
 
 ## Crate Examples