title: AttributeError: 'module' object has no attribute 'to_rgb'
body: <p>I wrote a simple code to form taylor digram using skillmetrics package. I used python version Python 2.7.12. The code is as follows:-</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import pandas as pd
  import numpy as np
  import skill_metrics as sm
  fire=pd.read_csv('fire.csv')
  PMfire = zip(fire['Date'],fire['PM_fire'],fire['Embassy_PM'])
  #taylor_stats1 = sm.taylor_statistics('PM_fire','Embassy_PM','Date')
  o= {"Data":fire['Embassy_PM'],'Date':fire['Date']}# form date and and embassy datas
  p= {"Data":fire['PM_fire'],'Date':fire['Date']}# form  dictionary containg pm_fire and date
  # Calculate statistics for Taylor diagram
      # The first array element corresponds to the reference series 
      # for the while the second is that for the predicted series.
  taylor_stats1 = sm.taylor_statistics(p,o,'Data')
  sdev = np.array([taylor_stats1['sdev'][0]])# Calculate standard deviation
  crmsd = np.array([taylor_stats1['crmsd'][0]])#Calculate root mean square difference
  ccoef = np.array([taylor_stats1['ccoef'][0]])# Calculate correlation coefficient
  sm.taylor_diagram(sdev,crmsd,ccoef)#form taylor digram
  plt.savefig('taylor.png')
  plt.show()
  </code></pre>
  
  <p>But, it is giving me error.The error is as follows:-</p>
  
  <pre><code>  File "&lt;ipython-input-2-edf3b67792d8&gt;", line 1, in &lt;module&gt;
      runfile('/home/mala/Downloads/F/taylor_plot.py', wdir='/home/mala/Downloads/F')
  
    File "/usr/lib/python2.7/dist-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 699, in runfile
      execfile(filename, namespace)
  
    File "/usr/lib/python2.7/dist-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 81, in execfile
      builtins.execfile(filename, *where)
  
    File "/home/mala/Downloads/F/taylor_plot.py", line 21, in &lt;module&gt;
      sm.taylor_diagram(sdev,crmsd,ccoef)
  
    File "/usr/local/lib/python2.7/dist-packages/skill_metrics/taylor_diagram.py", line 110, in taylor_diagram
      plot_pattern_diagram_markers(X,Y,option)
  
    File "/usr/local/lib/python2.7/dist-packages/skill_metrics/plot_pattern_diagram_markers.py", line 104, in plot_pattern_diagram_markers
      rgba = clr.to_rgb(option['markercolor']) + (alpha,)
  
  AttributeError: 'module' object has no attribute 'to_rgb'
  </code></pre>