Support `#[cfg(..)]` on fields

Fixed

• Support attribute evaluation, e.g. #[cfg(..)] on fields.

Changed

• Breaking Change: Upgraded MSRV to Rust 1.57.
• Upgraded to Rust edition 2021.
• Breaking Change: To prevent breaking invariants, skip groups were
  introduced: Debug, EqHashOrd, Hash and Zeroize.

Don't require `#[derive(DeriveWhere)]`

Added

• Support ZeroizeOnDrop.

Changed

• Breaking Change: Changed to attribute instead of derive proc-macro.

Removed

• Breaking Change: Remove support for Zeroize(drop).

Initial Release

v1.0.0-rc.1

fix publish