BUG: Unexpected behaviour comparison dataframes with None values
- [x ] I have checked that this issue has not already been reported.

- [ x] I have confirmed this bug exists on the latest version of pandas.

- [ ] (optional) I have confirmed this bug exists on the master branch of pandas.

---

**Note**: Please read [this guide](https://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports) detailing how to provide the necessary information for us to reproduce your bug.

#### Code Sample, a copy-pastable example

```python
np.nan == np.nan
# False

pd.Series(index=[0], data=[np.nan]) == pd.Series(index=[0], data=[np.nan])
# False

None == None
# True

pd.Series(index=[0], data=[None]) == pd.Series(index=[0], data=[None])
# False

```

#### Problem description

If None==None equals True, I had expected that pd.Series(index=[0], data=[None]) == pd.Series(index=[0], data=[None]) would also equal True.

I have pandas version 1.0.5

#### Expected Output

pd.Series(index=[0], data=[None]) == pd.Series(index=[0], data=[None])
# True

#### Output of ``pd.show_versions()``


</details>

INSTALLED VERSIONS
------------------
commit           : None
python           : 3.6.10.final.0
python-bits      : 64
OS               : Linux
OS-release       : 4.14.171-105.231.amzn1.x86_64
machine          : x86_64
processor        : x86_64
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 1.0.5
numpy            : 1.16.2
pytz             : 2019.3
dateutil         : 2.8.0
pip              : 20.0.2
setuptools       : 46.1.3.post20200330
Cython           : None
pytest           : 5.3.5
hypothesis       : None
sphinx           : 2.4.3
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : 4.5.0
html5lib         : None
pymysql          : None
psycopg2         : 2.8.4 (dt dec pq3 ext lo64)
jinja2           : 2.11.1
IPython          : 7.12.0
pandas_datareader: None
bs4              : None
bottleneck       : None
fastparquet      : None
gcsfs            : None
lxml.etree       : 4.5.0
matplotlib       : None
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : 0.15.1
pytables         : None
pytest           : 5.3.5
pyxlsb           : None
s3fs             : 0.4.0
scipy            : 1.4.1
sqlalchemy       : 1.3.13
tables           : None
tabulate         : 0.8.6
xarray           : None
xlrd             : None
xlwt             : None
xlsxwriter       : None
numba            : None