title: ValueError: unknown format is not supported : ROC Curve
body: <p>I have just updated python version from 3.5 to 3.7 and getting an error in constructing ROC curve. I did not change anything in code but it gives some unknown error</p>
  <p><strong>Code</strong></p>
  <pre><code># ROC Curve
  
  from sklearn.metrics import confusion_matrix, accuracy_score, roc_auc_score, roc_curve
  y_pred_proba = predictions[::, 1]
  print(&quot;y_pred_proba&quot;, y_pred_proba)
  print(&quot;y_test&quot;, y_test)
  
  fpr, tpr, _ = roc_curve(y_test, y_pred_proba)
  auc = roc_auc_score(y_test, y_pred_proba)
  
  plt.figure(figsize=(7, 3))
  </code></pre>
  <p><strong>Values</strong></p>
  <p><strong>y_pred_proba</strong> [0.1746994  0.22792926 0.60020134 0.60857445 0.38630289 0.16318228
  0.20503542 0.76781874 0.89951127 0.13657112 0.36836385 0.23833946
  0.43924601 0.9874083  0.98404103 0.1003149  0.94596688 0.36480605
  0.48716601 0.04158647 0.8624937  0.93881636 0.54065999 0.38538261
  0.48002784 0.9874083  0.76781874 0.95791353 0.48002784 0.2448756
  0.98404103 0.06473023 0.34080482 0.11897602 0.07883822 0.08000581
  0.38630289 0.2546955  0.95515939 0.47123327 0.93544655 0.52027235
  0.23231433 0.45185196 0.78456432 0.92415415 0.22408711 0.82322069
  0.12670252 0.50150037 0.2546955  0.93881636 0.33043862 0.52027235
  0.07964735 0.11961717 0.79551265 0.0378607  0.34080482 0.87411928
  0.85397911 0.9874083  0.18885285 0.93140091 0.87411928 0.52027235
  0.48716601 0.19411124 0.06473023 0.79551265 0.76781874 0.81180605
  0.06833817 0.45406719 0.54006639 0.48002784 0.12468554 0.38630289
  0.18068918 0.9874083  0.79551265 0.43924601 0.86979492 0.15120609
  0.56046085 0.27958234 0.50261158 0.23231433 0.42496329 0.98404103
  0.93881636 0.96244002 0.38049589 0.9874083  0.38354959 0.8624937
  0.48716601 0.89951127 0.98404103 0.37245044 0.38630289 0.49835809
  0.9874083  0.27773467 0.98404103 0.40968608 0.3587635  0.1003149
  0.2572435  0.52492011 0.19933781 0.38538261 0.24401876 0.06473023
  0.82322069]</p>
  <p><strong>y_test</strong> [1 0 1 0 0 1 0 0 1 0 0 0 0 1 1 0 1 0 0 0 1 1 1 0 1 1 1 0 0 0 1 0 0 0 0 1 1
  0 1 1 1 0 0 1 0 1 0 1 0 1 1 1 1 1 0 0 1 0 0 1 0 1 0 1 1 1 1 0 0 1 1 1 0 1
  1 0 0 0 0 1 1 0 1 0 0 0 0 0 0 1 1 1 0 1 0 1 1 1 1 0 0 1 1 0 1 0 0 0 1 0 0
  0 0 0 1 0 0 0 0 1 0 1 0 0 0 1 1 0 1 0 0 1 0 0 0 0 1 1 1 1 1 0 1 0 0 0 0 0
  0 1 1 1 0 0 1 1 1 01]</p>
  <pre><code>Traceback (most recent call last):
    File &quot;/home/khawar/deepface/tests/Ensemble-Face-Recognition.py&quot;, line 897, in &lt;module&gt;
      fpr, tpr, _ = roc_curve(y_test, y_pred_proba)
    File &quot;/home/khawar/.local/lib/python3.6/site-packages/sklearn/utils/validation.py&quot;, line 72, in inner_f
      return f(**kwargs)
    File &quot;/home/khawar/.local/lib/python3.6/site-packages/sklearn/metrics/_ranking.py&quot;, line 776, in roc_curve
      y_true, y_score, pos_label=pos_label, sample_weight=sample_weight)
    File &quot;/home/khawar/.local/lib/python3.6/site-packages/sklearn/metrics/_ranking.py&quot;, line 539, in _binary_clf_curve
      raise ValueError(&quot;{0} format is not supported&quot;.format(y_type))
  ValueError: unknown format is not supported
  </code></pre>