Use pylint on Python 3 for inspections

Signed-off-by: Michal Čihař <michal@cihar.com>

.scrutinizer.yml

@@ -4,7 +4,7 @@ checks:
         duplicate_code: true
 tools:
     pylint:
-        python_version: '2'
+        python_version: '3'
         config_file: 'ci/pylint-scrutinizer.rc'
 filter:
     excluded_paths: