* Problem: Source files contain no license info
Solution: Add comments with SPDX license info to source files
* Python 3 files don't need # -*- coding: utf-8 -*-
* Problem: Need a method to initiate a new upsert-validator election
Solution: Added subcommand `new` to `upsert_validator`
* Problem: Changes to upsert-validator needed to be reflected in the docs
Solution: Wrote a section for `upsert-validator new`
* Problem: Docs for BEP#3 implementation not updated
Solutions: Update docs for #2070 and #2106
* Problem: 'Validator update' docs language not clear
Solution: Re-write the documentation which explains when validators are updated
* Problem: Typos and BEP reference missing
Solution: Fix typos and add BEP reference
* Document changes in the configure command.
Document new add/remove replicas commands.
* updated quickstart with mongodb instructions
* Docs on how to setup mongodb dev node with and without docker.
Update replSet option in docker-compose
* Fixed typo.
More explicit on how to run the tests.
* Fixed typo in mongodb docker instructions.
More explicit about requiring mongodb 3.4+
