title: jaccard_similarity_score raises ValueError: continuous-multioutput is not supported
body: <p>I would like to compute similarity between clusters, producted by using KMeans, using Jaccard index (from sklearn.metrics import jaccard_similarity_score). These may be a matrix which contains specific values: at [i,j] should be similarity between cluster i and j. My code for now:</p>
  
  <pre><code>from sklearn import datasets
  from sklearn.cluster import KMeans
  from sklearn.metrics import jaccard_similarity_score
  iris = datasets.load_iris()
  X = iris.data
  kmeans = KMeans(n_clusters=3).fit(X)
  labels = kmeans.labels_
  
  for i in range(3):
          for j in range(3):
              print(jaccard_similarity_score(X[np.where(labels==i)], X[np.where(labels==j)]))
  </code></pre>
  
  <p>But I've got the following error:</p>
  
  <pre><code>Traceback (most recent call last):
  
    File "&lt;ipython-input-15-e7b8e4471987&gt;", line 3, in &lt;module&gt;
      print(jaccard_similarity_score(X[np.where(labels==i)], X[np.where(labels==j)]))
  
    File "C:\Anaconda3\envs\p3\lib\site-packages\sklearn\metrics\classification.py", line 383, in jaccard_similarity_score
      y_type, y_true, y_pred = _check_targets(y_true, y_pred)
  
    File "C:\Anaconda3\envs\p3\lib\site-packages\sklearn\metrics\classification.py", line 89, in _check_targets
      raise ValueError("{0} is not supported".format(y_type))
  
  ValueError: continuous-multioutput is not supported
  </code></pre>