Initial Interop Updates (#492)

* Add interop chain spec and rename chain_id

* Add ability to connect to raw libp2p nodes

* Adds Identify protocol, clean up RPC protocol name handling

* Update to latest libp2p, gossipsub improvements

* Updates to latest interop branch.

- Shifts decoding of objects into message handler.
- Updates to latest interop gossipsub.
- Adds interop spec constant.

* Configuration updates allow for verbosity CLI flag and spec constants

* Update submodules to master

* Correct minimal chainspec modifications

* Duplication of validator polls are no longer fatal

* Apply PR suggestions

beacon_node/rpc/src/attestation.rs

@@ -1,6 +1,6 @@
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use eth2_libp2p::PubsubMessage;
-use eth2_libp2p::TopicBuilder;
+use eth2_libp2p::Topic;
 use eth2_libp2p::BEACON_ATTESTATION_TOPIC;
 use futures::Future;
 use grpcio::{RpcContext, RpcStatus, RpcStatusCode, UnarySink};
@@ -11,7 +11,7 @@ use protos::services::{
 };
 use protos::services_grpc::AttestationService;
 use slog::{error, info, trace, warn};
-use ssz::{ssz_encode, Decode};
+use ssz::{ssz_encode, Decode, Encode};
 use std::sync::Arc;
 use tokio::sync::mpsc;
 use types::Attestation;
@@ -19,7 +19,7 @@ use types::Attestation;
 #[derive(Clone)]
 pub struct AttestationServiceInstance<T: BeaconChainTypes> {
     pub chain: Arc<BeaconChain<T>>,
-    pub network_chan: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
+    pub network_chan: mpsc::UnboundedSender<NetworkMessage>,
     pub log: slog::Logger,
 }
 
@@ -144,13 +144,13 @@ impl<T: BeaconChainTypes> AttestationService for AttestationServiceInstance<T> {
                 );
 
                 // valid attestation, propagate to the network
-                let topic = TopicBuilder::new(BEACON_ATTESTATION_TOPIC).build();
-                let message = PubsubMessage::Attestation(attestation);
+                let topic = Topic::new(BEACON_ATTESTATION_TOPIC.into());
+                let message = PubsubMessage::Attestation(attestation.as_ssz_bytes());
 
                 self.network_chan
                     .try_send(NetworkMessage::Publish {
                         topics: vec![topic],
-                        message: Box::new(message),
+                        message: message,
                     })
                     .unwrap_or_else(|e| {
                         error!(