Issue with _get_file_writer after recent commits

[MikkelAntonsen]

I'm trying out pytorch-lightning and I'm having an issue after commits 1fad1c7 and 3fba70a. When I do

from test_tube import Experiment
exp = Experiment(save_dir=cfg['log_dir'])
trainer = Trainer(experiment=exp, max_nb_epochs=1, train_percent_check=0.01)

the program crashes with

File "/home/user/anaconda3/envs/pytorchenv/lib/python3.7/site-packages/test_tube/log.py", line 504, in _get_file_writer
if self.purge_step is not None:
AttributeError: 'Experiment' object has no attribute 'purge_step'

because there are four attributes of Experiment that are never set, self.purge_step, self.filename_suffix, self.flush_secs.

[williamFalcon]

make sure you have the correct versions installed (bottom of main readme in lightning). pytorch 1.2.0 introduced breaking changes which are fixed given that you use the correct pytorch, lightning and test tube versions. ie: after 4.2 you need pytorch 1.2.0.

check the faq in the readme in lightning

[MikkelAntonsen]

My fault. I looked at the requirements.txt but missed the faq. Thanks:)