started implementing BeaconNode for AttestationGrpcClient; included correct epoch_map for instantiation of Attester (lighthouse-255)

validator_client/src/attester_service/attestation_grpc_client.rs

@@ -2,6 +2,7 @@ use protos::services_grpc::AttestationServiceClient;
 use std::sync::Arc;
 
 use attester::{BeaconNode, BeaconNodeError, PublishOutcome};
+use protos::services::ProduceAttestationDataRequest;
 use types::{AttestationData, FreeAttestation, Slot};
 
 pub struct AttestationGrpcClient {
@@ -20,6 +21,16 @@ impl BeaconNode for AttestationGrpcClient {
         slot: Slot,
         shard: u64,
     ) -> Result<Option<AttestationData>, BeaconNodeError> {
+        let mut req = ProduceAttestationDataRequest::new();
+        req.set_slot(slot.as_u64());
+        req.set_shard(shard);
+
+        let reply = self
+            .client
+            .produce_attestation_data(&req)
+            .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
+
+        // TODO: return correct AttestationData
         Err(BeaconNodeError::DecodeFailure)
     }
 
@@ -27,6 +38,7 @@ impl BeaconNode for AttestationGrpcClient {
         &self,
         free_attestation: FreeAttestation,
     ) -> Result<PublishOutcome, BeaconNodeError> {
+        // TODO: return correct PublishOutcome
         Err(BeaconNodeError::DecodeFailure)
     }
 }