Fixing flake and black issues in code, enabling  the same in tox

Change-Id: Id817198c20c039029c8b053e8eac0a8482d72a48
Signed-off-by: preethika.p <preethika.p@tataelxsi.co.in>
diff --git a/osm_lcm/vim_sdn.py b/osm_lcm/vim_sdn.py
index c81969a..1e5458c 100644
--- a/osm_lcm/vim_sdn.py
+++ b/osm_lcm/vim_sdn.py
@@ -1159,7 +1159,11 @@
             k8s_deploy_methods = db_k8scluster.get("deployment_methods", {})
             # for backwards compatibility and all-false case
             if not any(k8s_deploy_methods.values()):
-                k8s_deploy_methods = {"helm-chart": True, "juju-bundle": True, "helm-chart-v3": True}
+                k8s_deploy_methods = {
+                    "helm-chart": True,
+                    "juju-bundle": True,
+                    "helm-chart-v3": True,
+                }
             deploy_methods = tuple(filter(k8s_deploy_methods.get, k8s_deploy_methods))
 
             for task_name in deploy_methods: