* Use node-rpc extensions to support account_nextIndex.
* Remove todo.
* Update lock.
* Use new srml_system_rpc crate.
* Update to substrate=master
* Update lockfile.
* Update to polkadot-master.
* Apply suggestions from code review
Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>
Tomasz Drwięga