Bug Description
When trying to run alice grant in nucypher cli, it shows this error:
raise self.StampNotSigned nucypher.network.nodes.StampNotSigned

To Reproduce
Install nucypher version: 3.0.0 beta 3
Initialize ursula, alice and bob
then try command:
nucypher alice grant \ --bob-verifying-key <BOB_VERIFYING_KEY> \ --bob-encrypting-key <BOB_ENCRYPTING_KEY> \ --label Test \ --expiration 2020-10-08T10:07:50Z \ --m 1 --n 1 --value 1 --debug

Traceback
Finished action 'grant', stopping (Alice)⇀SlateGray Alembic Olive Peace↽ (0x1fA7F1C9782EBf8cB36bd83fEE0026e8ac1F3cB8) Disenchanting (Alice)⇀SlateGray Alembic Olive Peace↽ (0x1fA7F1C9782EBf8cB36bd83fEE0026e8ac1F3cB8) Traceback (most recent call last): File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/bin/nucypher", line 8, in <module> sys.exit(nucypher_cli()) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/click/core.py", line 829, in __call__ return self.main(*args, **kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/click/core.py", line 782, in main rv = self.invoke(ctx) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/click/core.py", line 1259, in invoke return _process_result(sub_ctx.command.invoke(sub_ctx)) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/click/core.py", line 1259, in invoke return _process_result(sub_ctx.command.invoke(sub_ctx)) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/click/core.py", line 1066, in invoke return ctx.invoke(self.callback, **ctx.params) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/click/core.py", line 610, in invoke return callback(*args, **kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/interfaces.py", line 60, in wrapped return c(*args, **kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/cli/options.py", line 163, in wrapper return func(**kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/cli/options.py", line 192, in wrapper return func(**kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/cli/options.py", line 163, in wrapper return func(**kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/cli/options.py", line 163, in wrapper return func(**kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/cli/commands/alice.py", line 470, in grant return ALICE.controller.grant(request=grant_request) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/controllers.py", line 99, in wrapper return self.handle_request(name, request=request) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/controllers.py", line 146, in handle_request response = self._perform_action(action=method_name, request=request) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/controllers.py", line 152, in _perform_action response_data = super()._perform_action(*args, **kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/controllers.py", line 63, in _perform_action response = method(**params) # < ---- INLET File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/interfaces.py", line 36, in wrapped return func(*args, **kwargs) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/control/interfaces.py", line 117, in grant new_policy = self.character.grant(bob=bob, File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/characters/lawful.py", line 312, in grant policy.make_arrangements(network_middleware=self.network_middleware, File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/policy/policies.py", line 510, in make_arrangements sampled_ursulas = self.sample(handpicked_ursulas=handpicked_ursulas, File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/policy/policies.py", line 546, in sample sampled_ursulas = self.sample_essential(quantity=target_sample_quantity, File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/policy/policies.py", line 757, in sample_essential self.alice.block_until_specific_nodes_are_known(to_check, learn_on_this_thread=discover_on_this_thread) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/nodes.py", line 658, in block_until_specific_nodes_are_known self.learn_from_teacher_node(eager=True) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/nodes.py", line 790, in learn_from_teacher_node response = self.network_middleware.get_nodes_via_rest(node=current_teacher, File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/middleware.py", line 284, in get_nodes_via_rest response = self.client.get(node_or_sprout=node, File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/middleware.py", line 107, in method_wrapper host, node_certificate_filepath, http_client = self.verify_and_parse_node_or_host_and_port(node_or_sprout, host, port) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/middleware.py", line 57, in verify_and_parse_node_or_host_and_port node.verify_node(network_middleware_client=self, registry=self.registry) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/nodes.py", line 1217, in verify_node self.validate_metadata(registry=registry) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/nodes.py", line 1177, in validate_metadata self.validate_worker(registry=registry) File "/home/local/ASUAD/kmhalgi/Nucypher/nucypher-venv/lib/python3.8/site-packages/nucypher/network/nodes.py", line 1143, in validate_worker raise self.StampNotSigned nucypher.network.nodes.StampNotSigned

System:

• OS Version: Ubuntu 20.04
• Nucypher Version: 3.0.0 beta 3