refactor eq and tests

[sbillinge]

atm this is not robust against adding new attributes. Can we build a version that uses self.__dict__?

I think I may have done something like that in the diffraction objects in diffpy.utils

[sbillinge]

this refers to code

def __eq__(self, other):
    if not isinstance(other, DataClusters):
        return False
    return (
        np.array_equal(self.x, other.x)
        and np.array_equal(self.y, other.y)
        and np.array_equal(self.data_order, other.data_order)
        and np.array_equal(self.clusters, other.clusters)
        and self.res == other.res
        and self.current_idx == other.current_idx
        and self.lastcluster_idx == other.lastcluster_idx
        and self.lastpoint_idx == other.lastpoint_idx
        and self.status == other.status
        and self.INIT == other.INIT
        and self.READY == other.READY
        and self.CLUSTERING == other.CLUSTERING
        and self.DONE == other.DONE
    )

in DataClusters