[MRG+1] Fix FeatureAgglomeration docs

The docs are not displayed properly here, http://scikit-learn.org/stable/modules/generated/sklearn.cluster.FeatureAgglomeration.html (I keep running into these)
I'm sorry but I'm unable to get this work. For example,

    f = FeatureAgglomeration()
    hasattr(f, "fit_predict")
    True
    del f.fit_predict
    AttributeError: fit_predict
    delattr(f, "fit_predict")
    AttributeError: fit_predict
    f = FeatureAgglomeration
    del f.fit_predict
    AttributeError: fit_predict

It does not work on both the object and the instance (and hence does not work when I add it after the class init) Doing `dir(f)` shows `fit_predict`!. I know I am doing something wrong but I'm not sure what.