* eth1DataMajorityVote draft
* Merge branch 'origin-master' into eth1-majority-voting
* small test change
* move minimal config's HeadOfVotingPeriodLength closer to sqroot(32)
* remove todo
* remove head period and simplify equality check
* extract private functions from eth1DataMajorityVote
* feature flag
* Merge branch 'origin-master' into eth1-majority-voting
* add bytes import to tests
* Merge branch 'master' into eth1-majority-voting
* re-run build
* Merge branch 'master' into eth1-majority-voting
* Merge branch 'master' into eth1-majority-voting
* Merge branch 'master' into eth1-majority-voting