Bump version to 2.0.0 because breaking changes using Decimal

Author: tommymalmqvist

Cargo.toml

@@ -3,7 +3,7 @@ name = "rust-ocpp"
 description = "ocpp 1.6 and 2.0.1 libraries"
 readme = "README.md"
 license = "MIT OR Apache-2.0"
-version = "1.0.5"
+version = "2.0.0"
 authors = ["Tommy Malmqvist <[email protected]"]
 homepage = "https://codelabs.se/"
 repository = "https://github.com/codelabsab/rust-ocpp"