restore Nodeconfiguration.read_known_nodes

nucypher/config/keyring.py

@@ -682,4 +682,4 @@ class NucypherKeyring:
         for rule, failure_message in rules:
             if not rule:
                 failures.append(failure_message)
-        return True if not failures else failures
+        return failures

nucypher/config/node.py

@@ -378,6 +378,10 @@ class NodeConfiguration:
             self.validate(config_root=self.config_root, no_registry=no_registry or self.federated_only)
         return self.config_root
 
+    def read_known_nodes(self):
+        self.known_nodes.update(self.node_storage.all(federated_only=self.federated_only))
+        return self.known_nodes
+
     def read_keyring(self, *args, **kwargs):
         if self.checksum_address is None:
             raise self.ConfigurationError("No account specified to unlock keyring")