BoardAra (tictactoe, connect four, othello, clobber, breakthrough)

[chooga]

Thank you for contributing to the CrazyAra repository.

Please shortly describe what you changed in the code.
implemented and tested different board game environments (tictactoe, connect four, othello, clobber, breakthrough)

Before submitting this PR, please make sure:

• You have read the first steps section in the programmer's guide
• You are using approved terminology
• You have pulled the latest updates from the main repository.

[chooga]

changes done before merging, maybe following changes need to be reverted in order to start BoardAra again.

• engine/src/uci/optionsuci.cpp: L.:204 Max and MeanInitPly were set to 0,0,99999 in BoardAra
• engine/src/rl/rl_training.py: L.:112 local import statement reverted; net.eval() wasn't used in BoardAra
• engine/src/rl/Dockerfile: L.:28 a different image was used (FROM nvcr.io/nvidia/mxnet:20.10-py3)
• DeepCrazyhouse/config/rl_config.py: L.:19 binary_name reverted
  L.:30 uci_variant can be set to tictactoe, cfour, clobber, flipersi, or breakthrough for BoardAra

[QueensGambit]

Hi @chooga , thanks for the PR.
It looks like the tests are failing due to read_string_from_file().

[QueensGambit]

We should probably also add some tests for MODE_BOARDGAME to ensure you can still build it and it won't break.

[QueensGambit]

Added unit test in 17f25c2.