* [WIP] support multiple validators in an attestation and rework runtime

* [WIP] More fixes to nostd and basic new AttestationRecord

* [WIP] finish runtime integration

* [WIP] Fix deps

* [WIP] some compile fixes

* Make consensus compile

* Make everything compile

* Fix authoring

* Fix doctest complain

* Fix reward check conditions and add attestation precondition

* Refactor to redunce number of for loops

* Use less constrained generic

* Add default reward scheme

* [WIP] refactor casper into store and impl

* Rework rewards mod

* Fix tests

* prune should happen before epoch inc

* Add beacon reward handlers

* Split casper func and casper data

* Add tests for current casper impl

* [WIP] update runtime to newest version

* Port crypto to edition 2018

* Port everything else and make it compile

* Fix start_time

* Fix compile

* Fix warnings in primitives

* Fix all warnings for no_std

* Fix warnings in consensus and cli

* Add a dummy new blockimport type

* Switch to dummy block importer

* Move LatestAttestations to block_import mod

* Init LatestAttestations in ShasperBlockImport

* Wrap client BlockImport with custom fork choice

* Update bls version

* Re-introduce aggregate signature support

* Move DigestItem to a separate mod

* CompatibleExtrinsic trait

* Expose API for validator id from attestation

* CompatibleExtrinsic impl

* Save and load latest attestations

* note_block for LatestAttestation

* Expose last finalized/justified slot from runtime

* Implement LMD-GHOST's is_new_best

* Update substrate reference

* Finish LMD-GHOST integration

* Remove old unused lmd-ghost crate

* README: LMD-GHOST is integrated

* Switch to own DigestItem impl

* Fix consensus compile

* H256 -> Self::Hash

Rework Shasper and add block authoring logic