Update to latest Substrate master. (#353)

* Integrate srml/im-online

* Fix all build errors with old aura.

* Fix most of the build errors.

* Builds and tests seem to pass (I will not trust this commit yet)

* Apply suggestions from code review

Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>

* Kill some warnings.

* fix panics on 0 validators

* Fix dev chain.

* Fix author stuff

* fix im online integration.

* Some tweaks

* Introduce app-crypto

* Initial build work

* codec update / tweaks

* patch polkadot-erasure-coding input

* More fixes for new crypto

* More fixes

* Update parachains module

* evamp parachain crypto

* More crypto work.

* Chain spec and service.

* ChainSpec stuff

* Last bits for a clean build

* Tweak coment

* adapt polkadot-validation to the new keystore

* polkadot-network compiles, but tests don't

* Integrate the new parachain validation stuff

* delete message_routing file

* make polkadot-network tests compile and pass

* runtime tests compile and pass

* update substrate ref

* service compiles

* all tests pass

* Add TODO, change branch back to polkadot-master

* Lock file

* TODOs done

* Issue number

* Remove old tODO

* Remove commented code

polkadot/runtime/src/attestations.rs

@@ -20,7 +20,7 @@
 //! as well.
 
 use rstd::prelude::*;
-use parity_codec::{Encode, Decode};
+use codec::{Encode, Decode};
 use srml_support::{decl_storage, decl_module, ensure};
 
 use primitives::{Hash, parachain::{AttestedCandidate, CandidateReceipt, Id as ParaId}};