fix: dioxus must specify rust versionand edition

Cargo.toml

@@ -2,13 +2,14 @@
 name = "dioxus"
 version = "0.1.8"
 authors = ["Jonathan Kelley"]
-edition = "2018"
+edition = "2021"
 description = "Core functionality for Dioxus - a concurrent renderer-agnostic Virtual DOM for interactive user experiences"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/DioxusLabs/dioxus/"
 homepage = "https://dioxuslabs.com"
 documentation = "https://dioxuslabs.com"
 keywords = ["dom", "ui", "gui", "react", "wasm"]
+rust-version = "1.56.0"
 
 [dependencies]
 dioxus-core = { path = "./packages/core", version = "^0.1.9" }