Skip nodes functionality for Package and Network modules

Added to main entrypoint
- Skip nodes using simple argument with '*' as a trailing wildcard
- Skip nodes using file list

Usability improovement
- Node list preview in status line
- Node stats alignment in net report

Minor fixes:
- Python version detection (3.5+)
- Node counter for each status
- Proper node skip handling

Change-Id: I086ef501bc06f0e739df25349257f1c63a2e2fcf
Related-PROD: PROD-35009
diff --git a/cfg_checker/modules/packages/__init__.py b/cfg_checker/modules/packages/__init__.py
index 41dfca1..2d0cc79 100644
--- a/cfg_checker/modules/packages/__init__.py
+++ b/cfg_checker/modules/packages/__init__.py
@@ -112,9 +112,12 @@
         _kw = [args.exclude_keywords]
 
     # init connection to salt and collect minion data
+    _skip, _skip_file = args_utils.get_skip_args(args)
     pChecker = checker.CloudPackageChecker(
         force_tag=args.force_tag,
-        exclude_keywords=_kw
+        exclude_keywords=_kw,
+        skip_list=_skip,
+        skip_list_file=_skip_file
     )
     # collect data on installed packages
     pChecker.collect_installed_packages()