* Renamed `Reportable` to `ThinContext`, the ZST value is now an associated type:
https://github.com/knox-networks/bigerror/blob/cda942ed9ac62fa0a02f9c1fcf4de0d7227b7b78/bigerror/src/lib.rs#L32-L36

* Added `bigerror-derive` to allow deriving `ThinContext`:
  https://github.com/knox-networks/bigerror/blob/cda942ed9ac62fa0a02f9c1fcf4de0d7227b7b78/bigerror/src/context.rs#L105-L107
  Note: `#[bigerror(crate)]` is only needed inside the `bigerror` crate, normal impls will use it like so:
  ```rust
  #[derive(ThinContext)]
  pub struct MyError;
  ```
* Renamed `ThinContext::with_*`  to use `ThinContext::attach_*`: https://github.com/knox-networks/bigerror/pull/17/commits/cda942ed9ac62fa0a02f9c1fcf4de0d7227b7b78

* Removed old `reportable`, `from_report`, and `to_report` macros