object has no attribute 'add_scalar'
I'm trying to use the default logger to record scalars for tensorboard using add_scalar but I get:
self.logger.add_scalar('loss/train_loss', 42, 42)
AttributeError: 'TestTubeLogger' object has no attribute 'add_scalar'
The docs say TestTubeLogger inherits from SummaryWriter so add_scalar should be ok.
Can anyone help?
What's your environment?

conda version (no venv) : 4.7.12
PyTorch version: 1.3.1
Lightning version: 0.5.3.2
Test-tube version: 0.7.3