`__add__` colorbar functionality with break control

colorbar_add_break.py

def add(colormaps, break_location=0.5):
    
    lhs_dict = colormaps[0]._segmentdata
    rhs_dict = colormaps[1]._segmentdata
    new_dict = dict(red=[], green=[], blue=[])

    # Scale rhs by half
    for key in rhs_dict:
        val_list = rhs_dict[key]
        print(key, val_list)
        for val in val_list:
            new_dict[key].append((val[0] * break_location, val[1], val[2]))

    # Append lhs
    for key in lhs_dict:
        val_list = lhs_dict[key]
        print(key, val_list)
        for val in val_list:
            new_dict[key].append((break_location + val[0] * (1.0 - break_location), val[1], val[2]))

    N = 256
    gamma = 1.0

    return colors.LinearSegmentedColormap('something', new_dict, N, gamma)