* 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
* attestationutil.AttestingIndices: Minor improvement on indices array allocation
* progress
* more progress on makes
* progress
* more progress
* Merge branch 'master' of github.com:prysmaticlabs/prysm into memory1
* gaz
* fmt and imports
* Merge branch 'master' into memory2
* Min()
* remove spaces
* Merge branch 'master' of github.com:prysmaticlabs/prysm into memory2
* revert beacon-chain/operations/attestations/kv/block.go
* partially revert beacon-chain/operations/attestations/kv/aggregated.go
* Merge branch 'master' into memory2
* Merge branch 'master' into memory2
* include new getter for block
* create block filters from indices
* give every block index a unique bucket
* construct block indices by bucket mmap
* almost done save for the block filters
* include block filters, need a few more small touches for fetching the proper indices by bucket
* full functionality to filter by parent root
* tests pass when using the same logic as attestations
* todo
* proper todo formatting
* first minimum slot range filter
* slot range filters pass
* more filter criteria passing
* tests passing
* add todos
* all block tests pass and work
* rem fmt
* range retrieval test
* fixed test conditions
* instantiate the other buckets
* simplify bucket lookups
* deprecate non map code
* revamp to remove old index prefixes
* create indices from data
* create indices from data
* fetch block roots by slot range
* better abstractions
* simpler abstractions
* roots rename
* comment
* preston feedback
* allow blocks without parent root
* begin indices approach
* use shard bucket
* continue the indices approach
* eliminate the filter checkers in favor of the single loop of root lookups
* elim extraneous println statement
* continue the indices approach
* intersection for multiple filter types works, but is complex, verbose, and nearly unreadable
* remove unused code
* table drive tests for byte slice intersections
* include all table driven tests
* gazelle imports
* better abstractions
* better comments
* variadic approach working
* transform to variadic
* comments
* comments
* separate bucket for indices for faster range scans
* attestation key as hash tree root of data and different indices buckets
* test pass
* default behavior without filter
* appropriate filter criterion errors if criterion does not apply to type
* better abstractions and prune keys on deletion
* better naming
* fix build
* fix build
* rem extraneous code
