@tensoralex I have created a notebook which shows how to use visdom with fastai code using callbacks. Thanks for linking the cycle-gan repository. It cleared up quite a few things.
Link to the notebook: https://github.com/TheShadow29/FAI-notes/blob/master/notebooks/Visdom-With-FastAI.ipynb
I have also posted it as another topic here : Using Visdom with fastai library
Edit : Corrected the link