Bump black up to 18.6b4

1 files changed, 2 insertions, 1 deletions

diff --git a/tasks.py b/tasks.py
index fb15728b..50b75762 100644
--- a/tasks.py
+++ b/tasks.py
@@ -145,6 +145,7 @@ ns.configure(
             "changelog_file": join(
                 www.configuration()["sphinx"]["source"], "changelog.rst"
             ),
-        }
+        },
+        "travis": {"black": {"version": "18.6b4"}},
     }
 )