CI: Failing TestDtype.test_check_dtype on master
https://travis-ci.org/github/pandas-dev/pandas/jobs/697381484#L3750

```
____________________ TestDtype.test_check_dtype[Int64Dtype] ____________________

[gw1] linux -- Python 3.9.0 /home/travis/virtualenv/python3.9-dev/bin/python

self = <pandas.tests.extension.test_integer.TestDtype object at 0x7f1440e52280>

data = <IntegerArray>

[   1,    2,    3,    4,    5,    6,    7,    8, <NA>,   10,   11,   12,   13,

   14,   15,   16,   17,...5,   86,   87,   88,   89,   90,   91,

   92,   93,   94,   95,   96,   97, <NA>,   99,  100]

Length: 100, dtype: Int64

    def test_check_dtype(self, data):

        dtype = data.dtype

    

        # check equivalency for using .dtypes

        df = pd.DataFrame(

            {"A": pd.Series(data, dtype=dtype), "B": data, "C": "foo", "D": 1}

        )

    

        # np.dtype('int64') == 'Int64' == 'int64'

        # so can't distinguish

        if dtype.name == "Int64":

            expected = pd.Series([True, True, False, True], index=list("ABCD"))

        else:

            expected = pd.Series([True, True, False, False], index=list("ABCD"))

    

        # FIXME: This should probably be *fixed* not ignored.

        # See libops.scalar_compare

        with warnings.catch_warnings():

            warnings.simplefilter("ignore", DeprecationWarning)

            result = df.dtypes == str(dtype)

    

>       self.assert_series_equal(result, expected)

pandas/tests/extension/base/dtype.py:84: 

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

pandas/tests/extension/base/base.py:13: in assert_series_equal

    return tm.assert_series_equal(left, right, *args, **kwargs)

pandas/_libs/testing.pyx:68: in pandas._libs.testing.assert_almost_equal

    cpdef assert_almost_equal(a, b,

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   raise_assert_detail(obj, msg, lobj, robj, index_values=index_values)

E   AssertionError: Series are different

E   

E   Series values are different (25.0 %)

E   [index]: [A, B, C, D]

E   [left]:  [True, True, False, False]

E   [right]: [True, True, False, True]

pandas/_libs/testing.pyx:183: AssertionError
```

There's a note there about not ignoring the warning. I wonder if that's been changed.