Enable pylint, black and flake8 in tox.ini

Change-Id: I5e252eb4802b79497a3fdfea63488668d8a8c692
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_nbi/html_out.py b/osm_nbi/html_out.py
index 89e2f67..f591a70 100644
--- a/osm_nbi/html_out.py
+++ b/osm_nbi/html_out.py
@@ -196,13 +196,11 @@
         if "Location" in response.headers:
             body += '<a href="{}"> show </a>'.format(response.headers["Location"])
         else:
-            _id = request.path_info[request.path_info.rfind("/") + 1:]
+            _id = request.path_info[request.path_info.rfind("/") + 1 :]
             body += (
                 '<a href="/osm/{}?METHOD=DELETE"> '
                 '<img src="/osm/static/delete.png" height="25" width="25"> </a>'
-            ).format(
-                request.path_info
-            )
+            ).format(request.path_info)
             if request.path_info.startswith(
                 "/nslcm/v1/ns_instances_content/"
             ) or request.path_info.startswith("/nslcm/v1/ns_instances/"):