Install graphviz correctely

[Billal-MOKHTARI]

# installs the binaries.
conda install graphviz

# installs the python frontend for GraphViz.
pip install graphviz

# installs the python frontend as well.
conda install python-graphviz

Or you can directly use

conda install graphviz python-graphviz

References

• https://www.appsilon.com/post/visualize-pytorch-neural-networks
• RedaOps/ann-visualizer#12