title: Matplotlib Savefig will NOT overwrite old files
body: <p>This seems like it must be a permissions issue on my machine. After a systems update on Windows 10, when I run:</p>
  
  <pre><code>import matplotlib.pyplot as plt
  #make figure
  plt.plot([1,2,3,4])
  plt.ylabel('some numbers')
  
  #save
  plt.savefig("./figs/my_plot.jpg")
  </code></pre>
  
  <p>It will create the figure the first time the code is run. If I make a change to the code (e.g. change label) and then re-run, the plot shown in a Jupyter Notebook is updated, but the file saved on  my machine is not! This is a new issues as of today, after a systems update was pushed out, so this seems like a likely culprit. Any insight for me to fix this issue, besides creating a new file name every time a change is made? </p>