Update package versions to 2019.2.15 and fix flake8

Change-Id: I491a6f23065189390f7287b1ce756ac5e88d2b99
diff --git a/cfg_checker/modules/network/checker.py b/cfg_checker/modules/network/checker.py
index 54dadb9..b65e14d 100644
--- a/cfg_checker/modules/network/checker.py
+++ b/cfg_checker/modules/network/checker.py
@@ -81,4 +81,4 @@
             errors_class=self.errors,
             skip_list=skip_list,
             skip_list_file=skip_list_file
-        )
\ No newline at end of file
+        )