Strip out old code

All of these files have been moved to either:

- https://github.com/sigp/lighthouse-beacon
- https://github.com/sigp/lighthouse-validator
- https://github.com/sigp/lighthouse-common

For rationale, see: https://github.com/sigp/lighthouse/issues/197

eth2/utils/ssz/src/impl_tree_hash.rs

@@ -1,79 +0,0 @@
-use super::ethereum_types::{Address, H256};
-use super::{merkle_hash, ssz_encode, TreeHash};
-use hashing::hash;
-
-impl TreeHash for u8 {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for u16 {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for u32 {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for u64 {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for usize {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for Address {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for H256 {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        ssz_encode(self)
-    }
-}
-
-impl TreeHash for [u8] {
-    fn hash_tree_root(&self) -> Vec<u8> {
-        if self.len() > 32 {
-            return hash(&self);
-        }
-        self.to_vec()
-    }
-}
-
-impl<T> TreeHash for Vec<T>
-where
-    T: TreeHash,
-{
-    /// Returns the merkle_hash of a list of hash_tree_root values created
-    /// from the given list.
-    /// Note: A byte vector, Vec<u8>, must be converted to a slice (as_slice())
-    ///       to be handled properly (i.e. hashed) as byte array.
-    fn hash_tree_root(&self) -> Vec<u8> {
-        let mut tree_hashes = self.iter().map(|x| x.hash_tree_root()).collect();
-        merkle_hash(&mut tree_hashes)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_impl_tree_hash_vec() {
-        let result = vec![1u32, 2, 3, 4, 5, 6, 7].hash_tree_root();
-        assert_eq!(result.len(), 32);
-    }
-}