Apparently PyPI package is incomplete, at least core/ and templates/ are missing.
$ tree /home/j/.local/lib64/python3.6/site-packages/vislib/
/home/j/.local/lib64/python3.6/site-packages/vislib/
├── __init__.py
├── __pycache__
│ ├── __init__.cpython-36.pyc
│ ├── taucharts.cpython-36.pyc
│ ├── treant.cpython-36.pyc
│ └── visjs.cpython-36.pyc
├── taucharts.py
├── treant.py
└── visjs.py
1 directory, 8 files
Apparently PyPI package is incomplete, at least core/ and templates/ are missing.