* Use fastssz when available
* fix tests
* fix most tests
* Merge branch 'master' into faster-hash-proto
* Merge refs/heads/master into faster-hash-proto
* Merge refs/heads/master into faster-hash-proto
* Merge refs/heads/master into faster-hash-proto
* fix last test
* Merge branch 'faster-hash-proto' of github.com:prysmaticlabs/prysm into faster-hash-proto-2
* lint
* fix last test
* fix again
* Update beacon-chain/cache/checkpoint_state_test.go
Co-Authored-By: terence tsao <terence@prysmaticlabs.com>
* Merge refs/heads/master into faster-hash-proto