* initial validator attesthead rewrite based on proposer rewrite
* proceed with fetching committees and tree hashing the canonical head at assigned attester slot
* complete filling the properties of attestation data and all associated root hashes
* add when to attest todo
* finish entire attester client logic
* tests with mocks checked in
* tests passing in client
* stubbed out server implementation
* fixed build due to old property
* regen mocks with new mockgen version
* fixed broken tests
* complete bazel build fix
* address some review comments
* deep proto test
* tests passing after checking for empty committee and crosslink root
* address nishant comments
* initialize beacon state separately
* extracting out testcase into another func
* creating function for simulated objects
* creating simulated object struct
* final clean up
* documentation
* lint
* adding chain advancer
* review comments
* replacing lib
* adding initialization for chain and new vars in struct
* added func
* fixing tests and all other bugs
* fixing tests
* docs
* adding a new nil block function
* adding test
* remove check for nil blocks
* godoc
* fixing merge conflicts, tests
* fix test
* able to bazel build beacon chain.. yay
* fixed package validator tests
* fixed a few more package tests (epoch, blockops, forkchoice)
* fixed all the tests! and lint. Woohoo
* moving committee helpers to own package
* more fixes at epoch processing
* fixed rewards and penalties tests
* fixed rest of the tests. yay
* implemented process pentalties and exit logic
* tests
* add MaxWithdrawalsPerEpoch to config
* preston's feedback, replaced index with idx
* s/e/penalizedEpoch
* removed blank line
