* begin using tree hash instead of hash for state and blocks
* replace with ssz
* rem references to vote cache
* replace all instances of state/block hash with root
* goimports
* almost every test in the world fails
* goimports
* all tests pass, tree hash across repo
* 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
* first commit, remote att types
* no more agg attestation proto
* regen mock
* only attestations
* proto
* att process
* fix att references
* more tests passing
* use att protos
* complete
* Update dependency com_github_deckarep_golang_set to v1 (#1159)
* Update dependency com_github_edsrzf_mmap_go to v1 (#1160)
* Update dependency com_github_go_stack_stack to v1 (#1161)
* Update dependency com_github_rs_cors to v1 (#1162)
* Update dependency in_gopkg_urfave_cli_v1 to v1 (#1163)
* change visibility
