fix logging config and add profiler test

[jeremyjordan]

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• Did you write any new necessary tests?
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What does this PR do?

Fixes #1236

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[codecov]

Codecov Report

Merging #1267 into master will increase coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #1267   +/-   ##
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  Coverage      92%     92%           
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  Files          61      61           
  Lines        3153    3154    +1     
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+ Hits         2886    2887    +1     
  Misses        267     267           

[Borda]

Let's get it done...

[williamFalcon]

@jeremyjordan what happens right now if i interrupt training for profiling?
it sounds like for the profiler to work i have to set max_epochs? is that documented?

[jeremyjordan]

@williamFalcon the profiler summary gets printed (or saved to file) in run_training_teardown https://github.com/PyTorchLightning/pytorch-lightning/blob/master/pytorch_lightning/trainer/training_loop.py#L621

this is called if:

• KeyboardInterrupt is caught
• epoch mets max_epochs threshold
• early stopping is triggered
• step mets max_steps threshold

i believe all of the cases are covered for when we want to log the profiler summary, as run_training_teardown is intended for whenever we stop a training run