Bump pylint version to support python3.8

pylint 2.2.2 which we currently use does not support python 3.8 [1].

Let's use a newer version of pylint.

pylint now declares strict versions for astroid and isort,
so we do not need to manage them in our test-requirements.txt.

All new checks are disabled temporarily. Let's visit them later and
judge whether we disable them permanently one by one.

[1] https://github.com/PyCQA/pylint/issues/2737

Change-Id: I106b250e632305365aaab4d881c9ba5ea93505b3

.pylintrc

@@ -12,6 +12,7 @@ disable=
 # "E" Error for important programming issues (likely bugs)
  method-hidden,
  no-member,
+ no-value-for-parameter,  # TODO
  not-callable,
 # "W" Warnings for stylistic problems or minor programming issues
  arguments-differ,
@@ -23,6 +24,7 @@ disable=
  keyword-arg-before-vararg,  # TODO
  pointless-string-statement,
  protected-access,
+ raise-missing-from,  # TODO
  redefined-builtin,
  redefined-outer-name,
  signature-differs,
@@ -31,6 +33,7 @@ disable=
  unused-argument,
  unused-wildcard-import,
  useless-else-on-loop,
+ using-constant-test,  # TODO
  wildcard-import,
 # "C" Coding convention violations
  abstract-method,
@@ -39,6 +42,7 @@ disable=
  bad-continuation,
  deprecated-lambda,
  global-statement,
+ import-outside-toplevel,  # TODO
  invalid-name,
  missing-docstring,
  superfluous-parens,
@@ -49,8 +53,11 @@ disable=
  duplicate-code,
  inconsistent-return-statements,  # TODO
  interface-not-implemented,
+ no-else-continue,  # TODO
+ no-else-raise,  # TODO
  no-else-return,
  no-self-use,
+ super-with-arguments,  # TODO
  too-many-ancestors,
  too-many-arguments,
  too-many-branches,
@@ -59,6 +66,7 @@ disable=
  too-many-locals,
  too-many-return-statements,
  too-many-statements,
+ unnecessary-comprehension,  # TODO
  useless-object-inheritance
 
 [Basic]

test-requirements.txt

@@ -9,17 +9,15 @@
 # Hacking should appear first in case something else depends on pep8
 hacking>=3.0.1,<3.1.0 # Apache-2.0
 #
-astroid==2.1.0 # LGPLv2.1
 bandit!=1.6.0,>=1.4.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 flake8-import-order==0.12 # LGPLv3
-isort<5 # MIT
 nodeenv>=0.9.4 # BSD
 pytest>=5.3.5 # MIT
 pytest-django>=3.8.0 # BSD (3 clause)
 pytest-html>=2.0.1 #MPL-2.0
 python-memcached>=1.59 # PSF
-pylint==2.2.2 # GPLv2
+pylint==2.6.0 # GPLv2
 selenium>=2.50.1 # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT