Add validator duties gRPC service to val. client

validator_client/src/duties/mod.rs

@@ -1,3 +1,9 @@
+mod grpc;
+mod service;
+#[cfg(test)]
+mod test_node;
+mod traits;
+
 use self::traits::{BeaconNode, BeaconNodeError};
 use bls::PublicKey;
 use slot_clock::SlotClock;
@@ -5,10 +11,6 @@ use spec::ChainSpec;
 use std::collections::HashMap;
 use std::sync::{Arc, RwLock};
 
-mod service;
-mod test_node;
-mod traits;
-
 pub use self::service::DutiesManagerService;
 
 #[derive(Debug, PartialEq, Clone, Copy, Default)]