[WIP][GSoC] CNN3D and MaxPool3D implementation for GSoC 2020

[surya2191997]

[Work Product] This pull request contains the code pertaining to the Google Summer of Code 2020 project Development of 3D CNN in TMVA. It implements the following features:

• 3D CNN layer for cpu and and tests for the same
• 3D MaxPool layer for cpu and tests for the same

Implementation for CUDA architecture is still WIP. The last commit is Added backward pass tests(1b82793). These features are yet to be merged. Detailed updates can be found on my blog post.

[phsft-bot]

Can one of the admins verify this patch?

[lmoneta]

@phsft-bot build

[phsft-bot]

Starting build on ROOT-debian10-i386/cxx14, ROOT-performance-centos7-multicore/default, ROOT-fedora30/cxx14, ROOT-fedora31/noimt, ROOT-ubuntu16/nortcxxmod, mac1014/python3, mac1015/cxx17, windows10/cxx14
How to customize builds

[phsft-bot]

Build failed on ROOT-ubuntu16/nortcxxmod.
Running on sft-ubuntu-1604-3.cern.ch:/build/workspace/root-pullrequests-build
See cdash.
See console output.

Failing tests:

• projectroot.runtutorials.test_import_pandas

[phsft-bot]

Build failed on windows10/cxx14.
Running on null:C:\build\workspace\root-pullrequests-build
See cdash.
See console output.

[lmoneta]

Hi Suryia,
this PR does not build when cuda is enables (tmva-gpu=On).
Can you please apply this patch to fix this:
https://cernbox.cern.ch/index.php/s/ZB4ij5to248um6u

Thank you

Lorenzo

[surya2191997]

Hi Suryia,
this PR does not build when cuda is enables (tmva-gpu=On).
Can you please apply this patch to fix this:
https://cernbox.cern.ch/index.php/s/ZB4ij5to248um6u

Thank you

Lorenzo

Thanks for the patch Lorenzo, I've updated the PR