Extending TPOT to unsupervised clustering

Hi, I'm excited with your TPOT tool and how it infers hyperparameters for binary classifiers. I was wondering whether you have any plans to extend TPOT to unsupervised machine learning, i.e. **clustering**?
## Context of the issue

Setting hyperparameters for various clustering algorithms in scikit-learn can be tricky similarly to unsupervised learning algorithms. It would be great if **clustering hyperparameters** could be automatically infered by TPOT in same way as it is performed for classifying algorithms.
I presume **silhouette coefficient** would be an adequate scoring method, because it is a measure of compactness and separation of clusters. It is already present in scikit-learn (see here: http://scikit-learn.org/stable/modules/generated/sklearn.metrics.silhouette_score.html)