Fix consensus, SSZ, tree hash & run merge EF tests (#2622)

* Update to v1.1.0-beta.4 (squash of #2548)

* SSZ, cached tree hash, EF tests

consensus/ssz_types/src/serde_utils/hex_fixed_vec.rs

@@ -0,0 +1,25 @@
+use crate::FixedVector;
+use eth2_serde_utils::hex::{self, PrefixedHexVisitor};
+use serde::{Deserializer, Serializer};
+use typenum::Unsigned;
+
+pub fn serialize<S, U>(bytes: &FixedVector<u8, U>, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+    U: Unsigned,
+{
+    let mut hex_string: String = "0x".to_string();
+    hex_string.push_str(&hex::encode(&bytes[..]));
+
+    serializer.serialize_str(&hex_string)
+}
+
+pub fn deserialize<'de, D, U>(deserializer: D) -> Result<FixedVector<u8, U>, D::Error>
+where
+    D: Deserializer<'de>,
+    U: Unsigned,
+{
+    let vec = deserializer.deserialize_string(PrefixedHexVisitor)?;
+    FixedVector::new(vec)
+        .map_err(|e| serde::de::Error::custom(format!("invalid fixed vector: {:?}", e)))
+}

consensus/ssz_types/src/serde_utils/hex_var_list.rs

@@ -0,0 +1,26 @@
+//! Serialize `VariableList<u8, N>` as 0x-prefixed hex string.
+use crate::VariableList;
+use eth2_serde_utils::hex::{self, PrefixedHexVisitor};
+use serde::{Deserializer, Serializer};
+use typenum::Unsigned;
+
+pub fn serialize<S, N>(bytes: &VariableList<u8, N>, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+    N: Unsigned,
+{
+    let mut hex_string: String = "0x".to_string();
+    hex_string.push_str(&hex::encode(&**bytes));
+
+    serializer.serialize_str(&hex_string)
+}
+
+pub fn deserialize<'de, D, N>(deserializer: D) -> Result<VariableList<u8, N>, D::Error>
+where
+    D: Deserializer<'de>,
+    N: Unsigned,
+{
+    let bytes = deserializer.deserialize_str(PrefixedHexVisitor)?;
+    VariableList::new(bytes)
+        .map_err(|e| serde::de::Error::custom(format!("invalid variable list: {:?}", e)))
+}

consensus/ssz_types/src/serde_utils/mod.rs

@@ -1,2 +1,4 @@
+pub mod hex_fixed_vec;
+pub mod hex_var_list;
 pub mod quoted_u64_fixed_vec;
 pub mod quoted_u64_var_list;