Bug report

Bug summary
When the seaborn style sheet is used, outlier points in plots generated with boxplot are not displayed.

Code for reproduction

%matplotlib notebook
import matplotlib.pyplot as plt
plt.style.use('seaborn')
plt.figure()
plt.boxplot([0,0,0,1])

Actual outcome

Expected outcome

Matplotlib version

• Operating system: Linux
• Matplotlib version: 3.0.1
• Matplotlib backend (print(matplotlib.get_backend())):
• Python version: 3
• Jupyter version (if applicable):
• Other libraries: