Tapas classifier experiment doesn't disable v2 tensorflow behaviour which leads to AttributeError

[Maxvgrad]

When running tapas_classifier_experiment.py leads to the error AttributeError: 'int' object has no attribute 'value'.

The issue happens because the file doesn't disable_v2_behavior

tapas_classifier_experiment

``` python tapas/experiments/tapas_classifier_experiment.py \ --use_tpu=False \ ... --eval_interactions_file="${BASE_DIR}/${FT_RESULTS_DIR}/interactions/random-split-1-dev.tfrecord" \ --predict_interactions_file="${BASE_DIR}/${FT_RESULTS_DIR}/interactions/test.tfrecord" \ --do_train ```

Error stacktrace

Traceback (most recent call last):
  File "tapas/experiments/tapas_classifier_experiment.py", line 589, in <module>
    app.run(main)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/absl/app.py", line 308, in run
    _run_main(main, args)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/absl/app.py", line 254, in _run_main
    sys.exit(main(argv))
  File "tapas/experiments/tapas_classifier_experiment.py", line 493, in main
    estimator.train(input_fn=train_input_fn, max_steps=total_steps)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/tpu_estimator.py", line 3083, in train
    rendezvous.raise_errors()
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/error_handling.py", line 150, in raise_errors
    six.reraise(typ, value, traceback)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/six.py", line 719, in reraise
    raise value
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/tpu_estimator.py", line 3078, in train
    saving_listeners=saving_listeners)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 349, in train
    loss = self._train_model(input_fn, hooks, saving_listeners)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1182, in _train_model
    return self._train_model_default(input_fn, hooks, saving_listeners)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1211, in _train_model_default
    self.config)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/tpu_estimator.py", line 2915, in _call_model_fn
    config)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/estimator.py", line 1170, in _call_model_fn
    model_fn_results = self._model_fn(features=features, **kwargs)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/tpu_estimator.py", line 3173, in _model_fn
    features, labels, is_export_mode=is_export_mode)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/tpu_estimator.py", line 1700, in call_without_tpu
    return self._call_model_fn(features, labels, is_export_mode=is_export_mode)
  File "/gpfs/space/home/ploter/.conda/envs/tapas_clean_env/lib/python3.7/site-packages/tensorflow_estimator/python/estimator/tpu/tpu_estimator.py", line 2031, in _call_model_fn
    estimator_spec = self._model_fn(features=features, **kwargs)
  File "/gpfs/space/home/ploter/projects/tapas/tapas/models/tapas_classifier_model.py", line 1044, in model_fn
    classification_class_index=classification_class_index)
  File "/gpfs/space/home/ploter/projects/tapas/tapas/models/tapas_classifier_model.py", line 701, in _get_classification_outputs
    hidden_size_agg = output_layer_aggregation.shape[-1].value
AttributeError: 'int' object has no attribute 'value'