Some deps cleanup

Author: vidartf

docs/environment.yml

@@ -3,6 +3,7 @@ name: pythreejs_docs
 channels:
   - conda-forge
 dependencies:
+- ipydatawidgets>=4.3.2
 - python=3.10
 - nodejs
 - numpy

setup.py

@@ -67,6 +67,7 @@
         'ipywidgets>=7.2.1',
         'ipydatawidgets>=1.1.1',
         'numpy',
+        'traitlets',
     ],
     'extras_require': {
         'test': [