pandas <1.0.5 is not compatible with numpy 1.20

[rly]

Description

With pandas==0.25.3 and numpy==1.20.3, python test.py reveals 9 errors, such as:

======================================================================
ERROR: test_getitem_int (common.test_table.DynamicTableRegionRoundTrip)
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Traceback (most recent call last):
  File "/mnt/c/Users/Ryan/Documents/NWB/hdmf/tests/unit/common/test_table.py", line 918, in test_getitem_int
    rec = self._getitem(0)
  File "/mnt/c/Users/Ryan/Documents/NWB/hdmf/tests/unit/common/test_table.py", line 891, in _getitem
    return table[arg]
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/hdmf/common/table.py", line 784, in __getitem__
    ret = self.get(key)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/hdmf/common/table.py", line 838, in get
    ret[name] = col.get(arg, df=df, **kwargs)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/hdmf/common/table.py", line 1091, in get
    ret = self.table.get(ret, df=df, **kwargs)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/hdmf/common/table.py", line 890, in get
    ret = pd.DataFrame(retdf, index=pd.Index(name=self.id.name, data=id_index))
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/frame.py", line 411, in __init__
    mgr = init_dict(data, index, columns, dtype=dtype)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/internals/construction.py", line 257, in init_dict
    return arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/internals/construction.py", line 82, in arrays_to_mgr
    arrays = _homogenize(arrays, index, dtype)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/internals/construction.py", line 322, in _homogenize
    val = sanitize_array(
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/internals/construction.py", line 712, in sanitize_array
    subarr = construct_1d_arraylike_from_scalar(value, len(index), dtype)
  File "/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/dtypes/cast.py", line 1233, in construct_1d_arraylike_from_scalar
    subarr = np.empty(length, dtype=dtype)
TypeError: Cannot interpret '<attribute 'dtype' of 'numpy.generic' objects>' as a data type

There are also many DeprecationWarnings between pandas and numpy such as:

/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/indexes/base.py:459: 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.
Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
/home/rly/miniconda3/envs/test/lib/python3.8/site-packages/pandas/core/internals/construction.py:588: DeprecationWarning: `np.object` is a deprecated alias for the builtin `object`. To silence this warning, use `object` by itself. Doing this will not modify any behavior and is safe.
Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations

See also numpy/numpy#18355

We can either set an upper bound on numpy to <1.20 or set a lower bound on pandas to >=1.0.5. Or just note this as an incompatible environment configuration in the README. I would prefer to upgrade pandas requirements so that we continue to get the latest updates with numpy.

Steps to Reproduce

Environment

Python Executable: Conda
Python Version: 3.8
Operating System: Windows, Linux
HDMF Version: 2.5.5

Checklist

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