Merge Beholder into TensorBoard

[chrisranderson]

@jart recommended just copying the files over at first without integrating things, so here are the copies. :)

[chrisranderson]

I'll take a look at fixing the paths tomorrow.

[jart]

Thank you Chris. We have two options:

1. (Preferred) Update the BUILD files with the new path structure, etc. so that bazel test //tensorboard/... passes. We can't merge unless Travis is green.

2. Move beholder from tensorboard/plugins to third_party/beholder which side-steps the issue entirely, as that directory is not tested by Travis.

[chrisranderson]

The paths look good, but my tests fail (likely because I'm expecting a certain directory to already exist, I'm thinking). I don't have much free time nowadays - I'm thinking I'll just remove the tests for now (clearly the best solution when your tests fail haha).

[chrisranderson]

@jart The copy-pasted ffmpeg stuff is an issue still, right?

[jart]

Yes. Is there any chance you could just whip up a quick non-generalized private function to do what it's doing, so that file can be removed?

[jart]

LGTM

Thank you so much for this amazing contribution!

[chrisranderson]

:) Woo hoo! You're welcome. May tons of people learn and benefit from it.

[mholt]

I know our lab will! I'm gonna use this as soon as it's in the regular pip package. Any idea when (or with which release) that will be?

[jart]

Beholder will most likely be released in TensorBoard 0.5 alongside TensorFlow 1.5. My best guess for when that would happen is January.

I don't expect you to wait that long. So I just registered tb-nightly which will be tf-nightly's doppelganger. Once I'm done putting some polish on Chris' amazing work, I'll write a cron script to update that package, so you can start using it right away (without having to build from source.)

cc: @gunan

[mholt]

Sounds amazing, thank you!!