New deprecation warning in trapping.py

[michael-petersen]

New warning about deprecation to run down -- feels like this could be made more clever anyway.

trapping.py:562: VisibleDeprecationWarning: Creating an ndarray from ragged nested sequences (which is a list-or-tuple of lists-or-tuples-or ndarrays with different lengths or shapes) is deprecated. If you meant to do this, you must specify 'dtype=object' when creating the ndarray
the_clusters = np.array([np.arctan(np.abs(np.array(K.clusters[i])[:,1])/np.abs(np.array(K.clusters[i])[:,0])) for i in range(0,k)])