Remove default output handling in tensorflow task

[andrewsmartin]

We should remove this default output behavior and instead have users be explicit.

[codecov]

Codecov Report

Merging #181 into master will decrease coverage by 0.05%.
The diff coverage is 75%.

@@            Coverage Diff             @@
##           master     #181      +/-   ##
==========================================
- Coverage   89.08%   89.02%   -0.06%     
==========================================
  Files          12       12              
  Lines         733      720      -13     
==========================================
- Hits          653      641      -12     
+ Misses         80       79       -1

Impacted Files	Coverage Δ
spotify_tensorflow/luigi/tensorflow_task.py	90.62% <75%> (-0.21%)	⬇️

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[daikeshi]

I just noticed this PR. It has been a while. LGTM! 👍

I'm fine with merging as it is although codcov is red. @brianmartin what do you think?

[andrewsmartin]

Sorry, forgot about this one. I think our codecov settings are a little whack, seems like every time it decreases it turns the build red (though I haven't really verified for sure). @daikeshi @brianmartin @rclough are you fine to merge this?