Bump Cumulus and Friends (#91)
* Bump Cumulus to commit `1dd000a0` * Bump `sp-io` to `c000780d` * Bump Polkadot to `d2681524` * Add `scale-info` crate * Fix breaking changes * Clippy! * RustFmt * Update Substrate commit in README
* Bump Cumulus to commit `1dd000a0` * Bump `sp-io` to `c000780d` * Bump Polkadot to `d2681524` * Add `scale-info` crate * Fix breaking changes * Clippy! * RustFmt * Update Substrate commit in README