Release parameterized_macro 3.0.0

Strictly speaking, a major version bump was unnecessary. However
since it's parent crate `parameterized` depends on "2", it would
require a release itself to match the changed unstable feature, and
might cause issues for those who (too) strictly depend on
`parameterized 2.0.0`. Choosing a major version bump for the
macro crate was the safe choice.

Author: foresterre

parameterized-macro/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "parameterized-macro"
-version = "2.1.0"
+version = "3.0.0"
 authors = ["Martijn Gribnau <garm@ilumeo.com>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"