This issue tracks the various tasks (in order) which need to be completed in order to implement upsert-validator i.e. BEP-21.

• Implement VALIDATOR_ELECTION spec. See PR Problem: (BEP-21) no way to propose validator election #2392
• Implement VALIDATOR_VOTE spec See PR Problem: Node operator cannot vote on a ValidatorElection #2428
• Track validator set in BigchainDB Problem: Validator set not tracked by BigchainDB #2436
• Implement upsert-validator transaction election process. See PR Problem: upsert-validator feature is error prone #2314 Problem: Cannot conclude validator election #2445
• Implement upsert-validator new E_PUBKEY E_POWER E_NODE_ID See PR Create dynamic upsert validator commands #2446
• Implement upsert-validator show <election_id> Create dynamic upsert validator commands #2457
• Implement upsert-validator approve <election_id> Problem: There is no way to vote for an election #2458
• Implement upsert-validator status <election_id>
• Add required tests for upsert-validator new No ABCI test for 'upsert-validator new' command #2460
• Update corresponding documentation, including the section titled Member: Dynamically Add a New Member to the Network --- See pull request Added docs & link re/ adding/removing validators #2570
• Update BEP-18 to reflect what was actually implemented
• Update BEP-21 to reflect what was actually implemented Problem: BEP-21 details were altered during implementation BEPs#80
• Update BEP-13 to reflect what was actually implemented Updated BEP-13 for elections & votes BEPs#90
• standardize public key format i.e. Tendermint encodes keys in base64 format when generating configs but during end_block it expects the public key to be base58 encoded. Problem: Upsert validator 'approve' command not transfering vote to election public key #2480 Problem: Public key format not standardized #2508
• remove experimental tag from documentation of upsert-validator