Remove np Deprecation Warning since `np.bool` is alias of `bool`

The warning report from test:

```
2021-04-30 15:29:32 /workspace/Paddle/build/python/paddle/fluid/framework.py:689: DeprecationWarning: `np.bool` is a deprecated alias for the builtin `bool`. To silence this warning, use `bool` by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use `np.bool_` here.
2021-04-30 15:29:32 Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
2021-04-30 15:29:32   elif dtype == np.bool:
2021-04-30 15:29:32 /workspace/Paddle/build/python/paddle/fluid/layers/utils.py:77: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working
2021-04-30 15:29:32   return (isinstance(seq, collections.Sequence) and
2021-04-30 15:29:32 /workspace/Paddle/build/python/paddle/fluid/tests/unittests/test_cond.py:99: DeprecationWarning: `np.bool` is a deprecated alias for the builtin `bool`. To silence this warning, use `bool` by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use `np.bool_` here.
```