pylint: Update pylint to 1.7.1, run on tests/ and tools and fix complaints.

The motivation for this is that
 a.) 1.7.1 runs with python 3.6 (bionic)
 b.) we want to run pylint on tests/ and tools for the same reasons
     that we want to run it on cloudinit/

The changes are described below.
- Update tox.ini to invoke pylint v1.7.1.
- Modify .pylintrc generated-members ignore mocked object members (m_.*)
- Replace "dangerous" params defaulting to {}
- Fix up cloud_tests use of platforms
- Cast some instance objects to with dict()
- Handle python2.7 vs 3+ ConfigParser use of readfp (deprecated)
- Update use of assertEqual(<boolean>, value) to assert<Boolean>(value)
- replace depricated assertRegexp -> assertRegex
- Remove useless test-class calls to super class
- Assign class property accessors a result and use it
- Fix missing class member in CepkoResultTests
- Fix Cheetah test import

1 files changed, 3 insertions, 3 deletions

diff --git a/tests/unittests/test_util.py b/tests/unittests/test_util.py
index 71f59529..787ca208 100644
--- a/tests/unittests/test_util.py
+++ b/tests/unittests/test_util.py
@@ -695,9 +695,9 @@ class TestSubp(helpers.CiTestCase):
         util.write_file(noshebang, 'true\n')
 
         os.chmod(noshebang, os.stat(noshebang).st_mode | stat.S_IEXEC)
-        self.assertRaisesRegexp(util.ProcessExecutionError,
-                                'Missing #! in script\?',
-                                util.subp, (noshebang,))
+        self.assertRaisesRegex(util.ProcessExecutionError,
+                               'Missing #! in script\?',
+                               util.subp, (noshebang,))
 
     def test_returns_none_if_no_capture(self):
         (out, err) = util.subp(self.stdin2out, data=b'', capture=False)