Checkpooint Callback not called when training GAN from documentation
I tried to add a model checkpoint callback to the GAN example from the documentation (https://github.com/PyTorchLightning/pytorch-lightning/blob/master/pl_examples/domain_templates/gan.py), but it is failing silently; no checkpoints are being written.  I can't find anything in the checkpoint docs that indicate why it is not working.
What's your environment?

OS: Linux
Packaging: Conda
Version : 0.6, pytorch 1.4