Update packages/python/chart-studio/chart_studio/tests/test_optional/test_matplotlylib/test_plot_mpl.py

Author: emmanuelle

packages/python/chart-studio/chart_studio/tests/test_optional/test_matplotlylib/test_plot_mpl.py

@@ -19,7 +19,7 @@
 if matplotlylib:
     import matplotlib.pyplot as plt
 
-
+@pytest.mark.matplotlib
 class PlotMPLTest(TestCase):
     def setUp(self):
         py.sign_in("PlotlyImageTest", "786r5mecv0", plotly_domain="https://plot.ly")