title: Plotting KMF curve using lifelines in Pycharm exit code 0 but no output
body: <p>Sorry am quite new to this but I tried running some code and I get exit code 0 (no errors) but I do not see any output (in the Python console) 
  Am using PyCharm Python 3.7 with lifelines package </p>
  
  <pre><code>from lifelines import KaplanMeierFitter
  
  durations = [5,6,6,2.5,4,4]
  event_observed = [1, 0, 0, 1, 1, 1]
  
  ## create a kmf object
  kmf = KaplanMeierFitter()
  
  ## Fit the data into the model
  kmf.fit(durations, event_observed,label='Kaplan Meier Estimate')
  
  ## Create an estimate
  kmf.plot(ci_show=False) 
  </code></pre>