Remove grandpa liveness oracle (#1271)

* core: support broadcasting consensus message to all peers

* grandpa: remove liveness oracle

* node: always start grandpa on full nodes

* core: don't check for grandpa justifications on failed block imports

* core: fix network connectivity test

substrate/core/service/src/lib.rs

@@ -578,11 +578,8 @@ macro_rules! construct_service_factory {
 			) -> Result<Self::FullService, $crate::Error>
 			{
 				( $( $full_service_init )* ) (config, executor.clone()).and_then(|service| {
-					if let Some(key) = (&service).authority_key() {
-						($( $authority_setup )*)(service, executor, Arc::new(key))
-					} else {
-						Ok(service)
-					}
+					let key = (&service).authority_key().map(Arc::new);
+					($( $authority_setup )*)(service, executor, key)
 				})
 			}
 		}