Remove Trezor Imports and presence in setup.py; Deprecate libusb1 suport in-test.

nucypher/cli/hardware/backends.py

@@ -23,7 +23,7 @@ from collections import namedtuple
 class TrustedDevice(ABC):
     """
     An Abstract Base Class for implementing wallet-like functions for stakers
-    utilizing trusted hardware devices (e.g. trezor).
+    utilizing trusted hardware devices.
     This class specifies a few basic functions required for staking on the
     NuCypher network.
 

setup.py

@@ -105,8 +105,7 @@ BENCHMARKS_REQUIRE = [
 EXTRAS_REQUIRE = {'development': TESTS_REQUIRE,
                   'deployment': DEPLOY_REQUIRES,
                   'docs': DOCS_REQUIRE,
-                  'benchmark': BENCHMARKS_REQUIRE,
-                  'trezor': ['trezor[ethereum]']}
+                  'benchmark': BENCHMARKS_REQUIRE}
 
 setup(name=ABOUT['__title__'],
       url=ABOUT['__url__'],

tests/cli/conftest.py

@@ -24,10 +24,6 @@ import sys
 
 import pytest
 from click.testing import CliRunner
-from trezorlib import client as trezor_client
-from trezorlib import device as trezor_device
-from trezorlib import ethereum as trezor_eth
-from trezorlib.messages import EthereumMessageSignature
 
 from nucypher.blockchain.eth.registry import AllocationRegistry
 from nucypher.config.characters import UrsulaConfiguration
@@ -39,23 +35,6 @@ from nucypher.utilities.sandbox.constants import (
 from nucypher.utilities.sandbox.constants import MOCK_CUSTOM_INSTALLATION_PATH_2, INSECURE_DEVELOPMENT_PASSWORD
 
 
-# CI machines don't have libusb available, thus usb1 raises an OSError.
-# This is a hack around that so we can patch what we need to run on CI.
-try:
-    import usb1
-except OSError:
-    class mock_usb1:
-
-        class USBErrorNoDevice(Exception):
-            pass
-
-        class USBErrorBusy(Exception):
-            pass
-
-    usb1 = mock_usb1()
-    sys.modules['usb1'] = usb1
-
-
 @pytest.fixture(scope='module')
 def click_runner():
     runner = CliRunner()