Find the neighbour-vertices in the triangulation for the given vertex
        Searches self.simplices for vertex entries and sorts neighbours

def identify_vertex_neighbours(self, vertex):
        """
        Find the neighbour-vertices in the triangulation for the given vertex
        Searches self.simplices for vertex entries and sorts neighbours
        """
        simplices = self.simplices
        ridx, cidx = np.where(simplices == vertex)
        neighbour_array = np.unique(np.hstack([simplices[ridx]])).tolist()
        neighbour_array.remove(vertex)
        return neighbour_array