Bunch of DeprecationWarnings

[deeplook]

I'm getting a bunch of 14 DeprecationWarnings from pytest for ipyvolume 0.5.2 running with traitlets 4.3.3 (see below) some of which sound like it will definitely break in future releases traitlets, which worries me as it adds to my feeling of this package being no longer maintained. Any comment about this would be highly appreciated.

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/utils.py:19: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it will stop working
    if isinstance(v, collections.Mapping):

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/transferfunction.py:46: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    levels = traitlets.List(traitlets.CFloat, default_value=[0.1, 0.5, 0.8]).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/transferfunction.py:47: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    opacities = traitlets.List(traitlets.CFloat, default_value=[0.01, 0.05, 0.1]).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/transferfunction.py:48: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    widths = traitlets.List(traitlets.CFloat, default_value=[0.1, 0.1, 0.1]).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:43: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    traitlets.List(Unicode, [], allow_none=True),

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:102: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    traitlets.List(Unicode, [], allow_none=True),

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:213: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    camera_center = traitlets.List(traitlets.CFloat, default_value=[0, 0, 0]).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:239: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    xlim = traitlets.List(traitlets.CFloat, default_value=[0, 1], minlen=2, maxlen=2).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:240: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    ylim = traitlets.List(traitlets.CFloat, default_value=[0, 1], minlen=2, maxlen=2).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:241: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    zlim = traitlets.List(traitlets.CFloat, default_value=[0, 1], minlen=2, maxlen=2).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:243: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    matrix_projection = traitlets.List(traitlets.CFloat, default_value=[0] * 16, allow_none=True, minlen=16, maxlen=16).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipyvolume/widgets.py:244: DeprecationWarning: Traits should be given as instances, not types (for example, `Int()`, not `Int`). Passing types is deprecated in traitlets 4.1.
    matrix_world = traitlets.List(traitlets.CFloat, default_value=[0] * 16, allow_none=True, minlen=16, maxlen=16).tag(sync=True)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipywidgets/widgets/widget.py:412: DeprecationWarning: Passing unrecoginized arguments to super(PerspectiveCamera).__init__(width=400, height=500).
  object.__init__() takes exactly one argument (the instance to initialize)
  This is deprecated in traitlets 4.2.This error will be raised in a future release of traitlets.
    super(Widget, self).__init__(**kwargs)

conda_test/test_ipyvolume.py::test_ipyvolume
  /home/joyvan/conda/envs/work/lib/python3.7/site-packages/ipywidgets/widgets/widget.py:412: DeprecationWarning: Passing unrecoginized arguments to super(Scatter).__init__(selection=None).
  object.__init__() takes exactly one argument (the instance to initialize)
  This is deprecated in traitlets 4.2.This error will be raised in a future release of traitlets.
    super(Widget, self).__init__(**kwargs)