removed mlflow and custom logger tests

[williamFalcon]

@neggert
Had to disable the mlflow and custom logger tests because there's something very wrong with that abstraction. It was deleting the code in the folder... super weird.

Please take a look at it.

[neggert]

Oh, jeez. This is super broken on master. Didn't do that last time I touched it. I'll take a look.

[williamFalcon]

Tests passed on GPUs

tests/test_logging.py::test_testtube_logger PASSED                                            [  2%]
tests/test_logging.py::test_testtube_pickle PASSED                                            [  5%]
tests/test_models.py::test_multi_gpu_model_ddp2 PASSED                                        [  7%]
tests/test_models.py::test_early_stopping_cpu_model PASSED                                    [ 10%]
tests/test_models.py::test_running_test_pretrained_model_ddp PASSED                           [ 12%]
tests/test_models.py::test_lbfgs_cpu_model PASSED                                             [ 15%]
tests/test_models.py::test_default_logger_callbacks_cpu_model PASSED                          [ 17%]
tests/test_models.py::test_dp_resume PASSED                                                   [ 20%]
tests/test_models.py::test_running_test_after_fitting PASSED                                  [ 23%]
tests/test_models.py::test_running_test_without_val PASSED                                    [ 25%]
tests/test_models.py::test_running_test_pretrained_model PASSED                               [ 28%]
tests/test_models.py::test_running_test_pretrained_model_dp PASSED                            [ 30%]
tests/test_models.py::test_gradient_accumulation_scheduling PASSED                            [ 33%]
tests/test_models.py::test_multi_gpu_model_ddp PASSED                                         [ 35%]
tests/test_models.py::test_optimizer_return_options PASSED                                    [ 38%]
tests/test_models.py::test_single_gpu_batch_parse PASSED                                      [ 41%]
tests/test_models.py::test_no_val_module PASSED                                               [ 43%]
tests/test_models.py::test_no_val_end_module PASSED                                           [ 46%]
tests/test_models.py::test_simple_cpu PASSED                                                  [ 48%]
tests/test_models.py::test_amp_single_gpu PASSED                                              [ 51%]
tests/test_models.py::test_no_amp_single_gpu PASSED                                           [ 53%]
tests/test_models.py::test_cpu_restore_training PASSED                                        [ 56%]
tests/test_models.py::test_amp_gpu_ddp PASSED                                                 [ 58%]
tests/test_models.py::test_cpu_slurm_save_load PASSED                                         [ 61%]
tests/test_models.py::test_loading_meta_tags PASSED                                           [ 64%]
tests/test_models.py::test_dp_output_reduce PASSED                                            [ 66%]
tests/test_models.py::test_model_saving_loading PASSED                                        [ 69%]
tests/test_models.py::test_model_freeze_unfreeze PASSED                                       [ 71%]
tests/test_models.py::test_amp_gpu_ddp_slurm_managed PASSED                                   [ 74%]
tests/test_models.py::test_cpu_model_with_amp PASSED                                          [ 76%]
tests/test_models.py::test_cpu_model PASSED                                                   [ 79%]
tests/test_models.py::test_all_features_cpu_model PASSED                                      [ 82%]
tests/test_models.py::test_single_gpu_model PASSED                                            [ 84%]
tests/test_models.py::test_multi_gpu_none_backend PASSED                                      [ 87%]
tests/test_models.py::test_multi_gpu_model_dp PASSED                                          [ 89%]
tests/test_models.py::test_amp_gpu_dp PASSED                                                  [ 92%]
tests/test_models.py::test_ddp_sampler_error PASSED                                           [ 94%]
tests/test_models.py::test_multiple_val_dataloader PASSED                                     [ 97%]
tests/test_models.py::test_multiple_test_dataloader PASSED                                    [100%]