fixed linting errors

ran black
removed unused imports and variables

testing/test_cacheREADME.py

@@ -1,15 +1,11 @@
 from __future__ import absolute_import, division, print_function
-import sys
-import py
 import _pytest
-import pytest
-import os
-import shutil
 
 pytest_plugins = ("pytester",)
 
 
 class Helper(object):
+
     def check_readme(self, testdir):
         config = testdir.parseconfigure()
         readme = config.cache._cachedir.join("README.md")
@@ -17,6 +13,7 @@ class Helper(object):
 
 
 class TestReadme(Helper):
+
     def test_readme_passed(self, testdir):
         testdir.tmpdir.join("test_a.py").write(
             _pytest._code.Source(
@@ -26,8 +23,8 @@ class TestReadme(Helper):
         """
             )
         )
-        result = testdir.runpytest()
-        assert self.check_readme(testdir) == True
+        testdir.runpytest()
+        assert self.check_readme(testdir) is True
 
     def test_readme_failed(self, testdir):
         testdir.tmpdir.join("test_a.py").write(
@@ -38,5 +35,5 @@ class TestReadme(Helper):
         """
             )
         )
-        result = testdir.runpytest()
-        assert self.check_readme(testdir) == True
+        testdir.runpytest()
+        assert self.check_readme(testdir) is True