Finishing the pytest migration. (#1661)

* Removed run_all_in_graph_and_eager_mode in attention_wrapper_test.py.

* Refactoring.

* Some black bug.

* Done one test.

* Fuse functions.

* Rewrite with unittest2pytest.

* Moved function.

* Removed use gpu.

* Remove prints.

* Removed one assertAllclose.

* Removed some more self.

* Removed some more self.

* Moved function out of class.

* Removed one function.

* Removed some self.

* Moved a function out of tf.test.TestCase.

* Removed decorator.

* IIII

* Removed the run functions eagerly.

* Removed import.

* Removed is_multi.

* Removed self for batch.

* Removed some more self.

* Removed some more self.

* Removed some stuff.

* Unholy stuff there.

* Found a way to replace that.

* Works well.

* Removed self completely from function.

* Removed self from parameters.

* Managed to move the function.

* It works with pytest only.

* Fully converted to pytest.

* Minor simplification.

* Some comment.

* Removed some unused functions.

* Removed some elements from the test_no_deprecated_v1.

* Removed some files from blacklists.

* Forgot to remove run_eagerly.

* Removed tf.executing_eagerly.

Author: gabrieldemarmiesse

.flake8

@@ -27,12 +27,5 @@ per-file-ignores =
     tensorflow_addons/image/tests/utils_test.py:N802
     tensorflow_addons/image/tests/color_ops_test.py:N802
     tensorflow_addons/optimizers/tests/conditional_gradient_test.py:N802
-    tensorflow_addons/optimizers/tests/lazy_adam_test.py:N802
-    tensorflow_addons/seq2seq/tests/attention_wrapper_test.py:N802
-    tensorflow_addons/seq2seq/tests/basic_decoder_test.py:N802
-    tensorflow_addons/seq2seq/tests/decoder_test.py:N802
-    tensorflow_addons/seq2seq/tests/beam_search_decoder_test.py:N802
-    tensorflow_addons/seq2seq/tests/beam_search_ops_test.py:N802
-    tensorflow_addons/optimizers/tests/cyclical_learning_rate_test.py:N802
     # variable ... in function should be lowercase
     tensorflow_addons/callbacks/tests/time_stopping_test.py:N806