Pytorch-lightning: Add TRAINS experiment manager support

[bmartinn]

:train2: Add TRAINS experiment manager support

Integrate the TRAINS experiment manager with pytorch lightning.
Following TRAINS Issue #107

Motivation

Extend the compatibility of pytorch-lightning logger to support the TRAINS experiment manager.

Pitch

PR code can be reviewed here

[github-actions[bot]]

Hey, thanks for your contribution! Great first issue!

[bmartinn]

Thanks to @S-aiueo32 + documentation and type hinting, details here

Dear PyTorch-Lightning Team, Could I push the PR?

[Borda]

@bmartinn sure, PR is welcome :]
cc: @PyTorchLightning/core-contributors

[williamFalcon]

@bmartinn this logger is causing a lot of issues. please fix asap, otherwise we'll have to remove it.

@Borda can you elaborate on the issues?

Traceback (most recent call last):
  File "/home/waf251/media/falcon_kcgscratch1/software/miniconda3/envs/pl10/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/home/waf251/media/falcon_kcgscratch1/software/miniconda3/envs/pl10/lib/python3.7/site-packages/trains/backend_interface/logger.py", line 197, in run
    while not self._exit_event.wait(period or 1.0):
  File "/home/waf251/media/falcon_kcgscratch1/software/miniconda3/envs/pl10/lib/python3.7/site-packages/trains/logger.py", line 522, in flush
    return self._task.flush()
  File "/home/waf251/media/falcon_kcgscratch1/software/miniconda3/envs/pl10/lib/python3.7/site-packages/trains/task.py", line 751, in flush
    LoggerRoot.flush()
  File "/home/waf251/media/falcon_kcgscratch1/software/miniconda3/envs/pl10/lib/python3.7/site-packages/trains/debugging/log.py", line 92, in flush
    h.flush()
  File "/home/waf251/media/falcon_kcgscratch1/software/miniconda3/envs/pl10/lib/python3.7/logging/__init__.py", line 1009, in flush
    self.stream.flush()
ValueError: I/O operation on closed file.

[bmartinn]

@williamFalcon is this on the master branch?
How do I reproduce it?
There is a fix for this PR on this branch and it was merged to the master here

[Borda]

@bmartinn pls see #1352