edition 2018 -> 2021

Author: malcolmvr

Cargo.toml

@@ -3,7 +3,7 @@ name = "graphrs"
 version = "0.11.14"
 authors = ["Malcolm van Raalte <malcolm@van.raalte.ca>"]
 description = "graphrs is a Rust package for the creation, manipulation and analysis of graphs."
-edition = "2018"
+edition = "2021"
 license = "MIT"
 homepage = "https://github.com/malcolmvr/graphrs"
 repository = "https://github.com/malcolmvr/graphrs"