Merge branch 'master' of https://github.com/paritytech/parity-bridges-common...

Merge branch 'master' of https://github.com/paritytech/parity-bridges-common into feature/issue-parity-895

 Conflicts:
	bin/millau/runtime/src/rialto_messages.rs
	bin/rialto/runtime/src/millau_messages.rs