fix code quality issues x/2

tools/testing/tests/fido2.py

@@ -1,5 +1,4 @@
 from __future__ import print_function, absolute_import, unicode_literals
-import sys
 import time
 from random import randint
 import array

tools/testing/tests/tester.py

@@ -2,7 +2,7 @@ import time, struct
 
 from fido2.hid import CtapHidDevice
 from fido2.client import Fido2Client
-from fido2.ctap1 import CTAP1, ApduError
+from fido2.ctap1 import CTAP1
 from fido2.utils import Timeout
 
 from fido2.ctap import CtapError

tools/testing/tests/u2f.py

@@ -47,7 +47,7 @@ class U2FTests(Tester):
 
         with Test("Check bad CLA"):
             try:
-                res = self.ctap1.send_apdu(1, CTAP1.INS.VERSION, 0, 0, b"abc")
+                self.ctap1.send_apdu(1, CTAP1.INS.VERSION, 0, 0, b"abc")
             except ApduError as e:
                 assert e.code == 0x6E00