Fix pylint errors

Author: vmalloc

setup.cfg

@@ -16,7 +16,8 @@ testing =
     slash>=1.5.0
     Flask
     Flask-Loopback
-    pylint~=1.7.0
+    pylint~=1.9.0; python_version<'3.0'
+    pylint~=2.2.0; python_version>='3.0'
     pytest; python_version < '3.0'
     pytest>4.0; python_version >= '3.0'
     pytest-cov<2.6; python_version < '3.0'

tests/test_backslash.py

@@ -1,4 +1,4 @@
 # py.test style tests here
 
 def test_import():
-    import backslash  # pylint: disable=trailing-newlines, unused-variable,unused-import
+    import backslash  # pylint: disable=trailing-newlines, unused-variable, unused-import