Network check fixes

- Proper network mapping
- Proper reclass lookup
- VIP detection
- Simple error gathering
- IP shown as 'exploded', i.e. in CIDR format
- MTU matching and detection
- Errors class for handling errors, including codes and indices
- Summary and detailed errors view
- Flake8 refactoring

Change-Id: I8ee37d345bdc21c7ad930bf8305acd28f8c121c8
Related-PROD: PROD-28199
diff --git a/cfg_checker/common/__init__.py b/cfg_checker/common/__init__.py
index 297ace6..427bc76 100644
--- a/cfg_checker/common/__init__.py
+++ b/cfg_checker/common/__init__.py
@@ -1,13 +1,14 @@
-import os
 import const
 
-from settings import pkg_dir, config
-from other import Utils
 from log import logger, logger_cli
 
+from other import Utils
+
+from settings import config
+
 
 utils = Utils()
 const = const
 logger = logger
 logger_cli = logger_cli
-config = config
\ No newline at end of file
+config = config