* Implement basic tree hash caching
* Use spaces to indent top-level Cargo.toml
* Optimize BLS tree hash by hashing bytes directly
* Implement tree hash caching for validator registry
* Persist BeaconState tree hash cache to disk
* Address Paul's review comments
* Prototype for far_right push
* Add push method and tests
* Modify beacon_chain_builder for interop to use push instead of create
* Add Push method to MerkleTree
* Cargo fmt
* Remove redundant tests
* Fix typo
* Rename push to push_leaf
* Fix clippy warnings
* Add DepthTooSmall enum variant
* Avoid cloning in MerkleTree::push_leaf
* Add quickcheck test for push_leaf
* Cargo fmt updated
* Return err instead of using unwrap()
* Use enumerate instead of hard indexing
* Use if let and return string on error
* Fix typo in deposit_leave
* Fix cargo fmt
* Prototype for far_right push
* Add push method and tests
* Modify beacon_chain_builder for interop to use push instead of create
* Add Push method to MerkleTree
* Cargo fmt
* Remove redundant tests
* Fix typo
* Rename push to push_leaf
* Fix clippy warnings
* Add DepthTooSmall enum variant
* Avoid cloning in MerkleTree::push_leaf
* Add quickcheck test for push_leaf
* Cargo fmt updated
* Return err instead of using unwrap()
* Use enumerate instead of hard indexing
* Use if let and return string on error
* Fix typo in deposit_leave
* Change into_iter to iter
* Fix clippy 'easy' warnings
* Clippy eth2/utils
* Add struct NetworkInfo
* Clippy for types, utils, and beacon_node/store/src/iters.rs
* Cargo fmt
* Change foo to my_foo
* Remove complex signature
* suppress clippy warning for unit_value in benches
* Use enumerate instead of iterating over range
* Allow trivially_copy_pass_by_ref in serde_utils
* Rename `hashing` crate to `eth2_hashing`
* Add license, desc to eth2_hashing Cargo.toml
* Remove merkle root from eth2 hashing
* Remove old benches folder (zombied from old branch)
* Add docs to eth2_hashing
* Prepare tree_hash for publishing on crates.io
* Update deps to use crates.io instead of paths
* Update all crates to pull ssz from crates.io
* Remove cached_tree_hash, add patches to manifest
* Fix compile error in benches
* Remove unused code
* Fix fake_crypto compile error
