* Done
* Fixed lock
* Fixed all the tests
* Comments
* Fixed more tests
* Merge branch 'master' into better-head-obj
* Fixed more tests
* Merge branch 'better-head-obj' of git+ssh://github.com/prysmaticlabs/prysm into better-head-obj
* Prestons feedback & fixed test
* Nishant's feedback
* Participation edge case
* Gaz
* Merge branch 'master' into better-head-obj
* Merge branch 'master' of git+ssh://github.com/prysmaticlabs/prysm into better-head-obj
* Raul's feedback
* Merge branch 'better-head-obj' of git+ssh://github.com/prysmaticlabs/prysm into better-head-obj