Add black_nbconvert and watermark to dev reqs (#3958)

AlexAndorra · web-flow · commit cfa56a472b52 · 2020-06-13T11:43:06.000+02:00
diff --git a/requirements-dev.txt b/requirements-dev.txt
@@ -1,3 +1,4 @@
+black_nbconvert
 bokeh>=0.12.13
 coverage<5.0
 graphviz>=0.8.3
@@ -16,3 +17,4 @@ recommonmark>=0.4.0
 seaborn>=0.8.1
 sphinx-autobuild==0.7.1
 sphinx>=1.5.5
+watermark
