Bump version number to reflect breaking changes.

microrm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "microrm"
-version = "0.2.4"
+version = "0.3.0"
 edition = "2021"
 license = "BSD-4-Clause"
 authors = ["Kestrel <kestrel@flying-kestrel.ca>"]