* 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
* Fix syncing bugs by recursively attempting to process parents in the import queue, change BlockRootsIterator
* Swap from crossbeam channel to tokio mpsc
* Recursion fix
* Remove exess block processing
* Fix network lag, correct attestation topic
* Correct network poll logic
* Overhaul of SimpleSync and modify BlockRootsIterator to return start_slot
* Fix bug in tests relating to StateRootsIterator
* Remove old, commented-out heartbeat code.
* Tidy docs on import queue enum
* Change source logging msg in simple sync
* Rename function parameter in simple sync
* Use `BestBlockRootsIterator` in `reduced_tree`
* Update comments for `BestBlockRootsIterator`
* Fix duplicate dep in cargo.toml
