Merged Age's changes and ripped out heaps of now obsolete stuff in the validator client.

- Replaced most instances of PublicKey with KeyPair, since they need to be passed into each validator thread now.
 - Pulled out a bunch of FreeAttestations, and replaced with regular Attestations (as per Paul's suggestion)
 - Started generalising pubkeys to 'signers' (though they are still just Keypairs)
 - Added validator_index into a few structs where relevant
 - Removed the SlotClock and DutiesReader from the BlockProducer and Attester services, since this logic is now abstracted to the higher level process.
 - Added a Hash trait to the Keypair (rather than just pubkey) which assumes the Pubkey uniquely defines it.

eth2/types/src/attestation_duty.rs

@@ -6,4 +6,5 @@ pub struct AttestationDuty {
     pub slot: Slot,
     pub shard: Shard,
     pub committee_index: usize,
+    pub validator_index: usize,
 }

eth2/types/src/beacon_block_header.rs

@@ -37,6 +37,19 @@ impl BeaconBlockHeader {
     pub fn canonical_root(&self) -> Hash256 {
         Hash256::from_slice(&self.hash_tree_root()[..])
     }
+
+    /// Given a `body`, consumes `self` and returns a complete `BeaconBlock`.
+    ///
+    /// Spec v0.5.0
+    pub fn into_block(self, body: BeaconBlockBody) -> BeaconBlock {
+        BeaconBlock {
+            slot: self.slot,
+            previous_block_root: self.previous_block_root,
+            state_root: self.state_root,
+            body,
+            signature: self.signature,
+        }
+    }
 }
 
 #[cfg(test)]

eth2/types/src/beacon_state/epoch_cache.rs

@@ -92,6 +92,7 @@ impl EpochCache {
                         slot,
                         shard,
                         committee_index: k,
+                        validator_index: *validator_index,
                     };
                     attestation_duties[*validator_index] = Some(attestation_duty)
                 }

eth2/types/src/lib.rs

@@ -85,6 +85,6 @@ pub type AttesterMap = HashMap<(u64, u64), Vec<usize>>;
 pub type ProposerMap = HashMap<u64, usize>;
 
 pub use bls::{AggregatePublicKey, AggregateSignature, Keypair, PublicKey, SecretKey, Signature};
-pub use libp2p::floodsub::{Topic, TopicBuilder};
+pub use libp2p::floodsub::{Topic, TopicBuilder, TopicHash};
 pub use libp2p::multiaddr;
 pub use libp2p::Multiaddr;

eth2/types/src/test_utils/testing_beacon_state_builder.rs

@@ -23,6 +23,7 @@ pub fn keypairs_path() -> PathBuf {
 /// Builds a beacon state to be used for testing purposes.
 ///
 /// This struct should **never be used for production purposes.**
+#[derive(Clone)]
 pub struct TestingBeaconStateBuilder {
     state: BeaconState,
     keypairs: Vec<Keypair>,