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, 1 insertions, 1 deletions

diff --git a/.pylintrc b/.pylintrc
index b160ce7b..3ad36924 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -56,5 +56,5 @@ ignored-classes=optparse.Values,thread._local
 # List of members which are set dynamically and missed by pylint inference
 # system, and so shouldn't trigger E1101 when accessed. Python regular
 # expressions are accepted.
-generated-members=types,http.client,command_handlers
+generated-members=types,http.client,command_handlers,m_.*