Make broken_swiss_roll work with MPH2009 algorithms

[hackalog]

Hunt down why :

• Cannot complete broken-swiss-roll, KernelPCA combination
• Cannot complete broken-swiss-roll, LLE combination
• Cannot complete broken-swiss-roll, LaplacianEigenmaps combination
• Cannot complete broken-swiss-roll, Isomap combination
• Cannot complete difficult, KernelPCA combination
• Cannot complete difficult, LLE combination
• Cannot complete twinpeaks, HLLE combination

  algorithms = {'KernelPCA': KernelPCA(n_components=low_dimension, kernel='poly', degree=5),
            'LLE': LocallyLinearEmbedding(n_components=low_dimension, n_neighbors=10),
            'HLLE': LocallyLinearEmbedding(n_components=low_dimension, method='hessian', n_neighbors=10),
            'LaplacianEigenmaps': SpectralEmbedding(n_components=low_dimension, n_neighbors=10),
            'Isomap' : Isomap(n_components=low_dimension, n_neighbors=10),
           }

[hackalog]

the only real issue was twinpeaks/HLLE. Switch to eigen_solver=dense for that one