Progress bar in Jupyter adds newlines for each validation step
🐛 Bug
Pytorch lightning prints newlines when showing the validation progress bar. See attached screenshot.
This may be a bug with nested progress bars in tqdm. I'm using the recent tqdm 4.45.0; I also had the issue with tqdm 4.43.0.

To Reproduce
Steps to reproduce the behavior:
In a Jupyter notebook, run trainer.fit(model) on any model that has a validation step.
Code sample

Expected behavior
No newlines should be added.
Environment
cuda:
        GPU:
                Tesla K80
        available:           True
        version:             10.1
packages:
        numpy:               1.17.4
        pyTorch_debug:       False
        pyTorch_version:     1.4.0
        pytorch-lightning:   0.7.1
        tensorboard:         2.2.0
        tqdm:                4.45.0
system:
        OS:                  Linux
        architecture:
                64bit

        processor:           
        python:              3.7.3
        version:             #1 SMP Debian 4.9.168-1+deb9u4 (2019-07-19)

Additional context