pylint: Synchronize pylint plugin to ipatests code

Pylint is a static analysis tool and therefore, couldn't always
analyze dynamic stuff properly. Transformation plugins is a way
to teach Pylint how to handle such cases.

Particularly, with the help of FreeIPA own plugin, it is possible
to tell Pylint about instance fields having a duck-typing nature.

A drawback exposed here is that a static view (Pylint's) of code
should be consistent with an actual one, otherwise, codebase will
be polluted with various skips of pylint checks.

* added missing fields to ipatests.test_integration.base.IntegrationTest
* an attempt is made to clear `no-member` skips for ipatests
* removed no longer needed `pytest` module transformation

Related: https://pagure.io/freeipa/issue/8116
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Christian Heimes <cheimes@redhat.com>

ipatests/test_integration/test_installation.py

@@ -188,7 +188,7 @@ class TestInstallWithCA1(InstallTestBase1):
         https://pagure.io/freeipa/issue/7418
         """
         ldap_conf = paths.OPENLDAP_LDAP_CONF
-        base_dn = self.master.domain.basedn  # pylint: disable=no-member
+        base_dn = self.master.domain.basedn
         client = self.replicas[0]
         tasks.uninstall_master(client)
         expected_msg1 = "contains deprecated and unsupported " \