Release 0.3.0 with Macro Attributes for struct and fields

@fatihaziz: A new Contributor has joined.dto_mapper.
A special thanks that new contributor @fatihaziz that started the work on macro attributes for struct and fields

• Adding macro attributes features on struct, existing mapped fields and new fields

Changed

• BREAKING: Remove unstringify library crate dependency. it is no longer required for this version. You can uninstall it
  by issuing this command from your project. And remove any reference of it from your code base.

cargo remove unstringify

What's Changed

• PR: improving macro with adding attributes properties for struct by @fatihaziz in #11
• code refactoring changes with macro attributes added to mapped existing fields by @douggynix in #12
• adding new contributor to change log by @douggynix in #13

New Contributors

• @fatihaziz made their first contribution in #11

Full Changelog: 0.2.0...0.3.0