Log current and next staking ledgers in cron

[trevorbernard]

Problem

Manual intervention is required to maintain the list of exported epoch staking ledgers for a given Mina network. Here is an example of a helm cron in the Mina codebase: https://github.com/MinaProtocol/mina/blob/compatible/helm/cron_jobs/mainnet-dump-staking-ledger-cronjob.yaml

Acceptance Criteria

The cron should run in the middle of a epoch so it can export the current and next staking ledger. The interval should be the time in minutes for a 7140 slot epoch. To be safe, you can run it in half the time so you guarantee that at least one export will contain both.

Tasks

• Create helm cron file for dumping staking ledgers
• Ensure cron interval is 7140 slot minutes or smaller
• Provision s3 buckets to accept ledger dumps
• Modify cronjob.yml to pushing to said s3 bucket
• Update documentation/README