* Add database migrations, still need to update the API usage...
* gofmt goimports
* progress
* Merge branch 'master' of github.com:prysmaticlabs/prysm into index-migration
* use slot instead of index
* rename LastArchivedIndex to LastArchivedSlot
* rename LastArchivedIndexRoot to LastArchivedRoot
* remove unused HighestSlotStates method
* deprecate old key, include in migration
* deprecate old key, include in migration
* remove blocks index in migration
* rename bucket variable
* fix code to pass tests
* Merge branch 'master' of github.com:prysmaticlabs/prysm into index-migration
* gofmt, goimports
* fix
* Add state slot index
* progress
* lint
* fix build
* Merge branch 'master' of github.com:prysmaticlabs/prysm into index-migration
* kafka
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* remove SaveArchivedPointRoot, a few other big changes
* Merge branch 'index-migration' of github.com:prysmaticlabs/prysm into index-migration
* fix tests and lint
* lint again
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* block migration, some renaming
* gaz, gofmt
* add tests
* change index to uint bytes
* Merge branch 'index-migration' of github.com:prysmaticlabs/prysm into index-migration
* rm method notes
* stop if the bucket doesn't exist
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* @rauljordan pr feedback
* Simplify
* Merge refs/heads/master into index-migration
* Remove unused method, add roundtrip test
* gofmt
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge refs/heads/master into index-migration
* Merge branch 'master' of github.com:prysmaticlabs/prysm into index-migration
