Update package versions to 2019.2.15 and fix flake8

Change-Id: I491a6f23065189390f7287b1ce756ac5e88d2b99
diff --git a/cfg_checker/helpers/tgz.py b/cfg_checker/helpers/tgz.py
index 5be00e2..9ac84f2 100644
--- a/cfg_checker/helpers/tgz.py
+++ b/cfg_checker/helpers/tgz.py
@@ -55,7 +55,7 @@
             with tarfile.open(self.basefile, "r:gz") as tgz:
                 _tgzitem = tgz.extractfile(tgz.getmember(name))
                 if decode:
-                    return _tgzitem.read().decode('utf-8') 
+                    return _tgzitem.read().decode('utf-8')
                 else:
                     return _tgzitem.read()
         else: