pd.ExcelFile closes stream on destruction in pandas 1.0.0
#### Code Sample, a copy-pastable example if possible

```python3

import pandas as pd
print(pd.__version__)
a = open('some_file.xlsx', 'rb')
x = pd.ExcelFile(a)
del x
print(a.read())
```


#### Problem description

Above script behaves in different way in pandas 0.25.3 and 1.0.0:

```bash
$ python3 t1.py
0.25.3
b''
$ sudo pip3 install pandas --upgrade --quiet
$ python3 t1.py
1.0.0
Traceback (most recent call last):
  File "t1.py", line 6, in <module>
    print(a.read())
ValueError: read of closed file
```

It seems that stream is closed when ExcelFile is destroyed - and I don't see why.

#### Expected Output

I'd expect either notice in release notes, or the same output in 0.25.3 and 1.0.0.

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

<details>

INSTALLED VERSIONS
------------------
commit           : None
python           : 3.6.8.final.0
python-bits      : 64
OS               : Linux
OS-release       : 5.0.0-1028-gcp
machine          : x86_64
processor        : x86_64
byteorder        : little
LC_ALL           : None
LANG             : C.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 1.0.0
numpy            : 1.18.1
pytz             : 2019.3
dateutil         : 2.8.1
pip              : 9.0.1
setuptools       : 39.0.1
Cython           : None
pytest           : 4.3.0
hypothesis       : None
sphinx           : 1.8.5
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : 4.4.1
html5lib         : 0.999999999
pymysql          : None
psycopg2         : 2.8.3 (dt dec pq3 ext lo64)
jinja2           : 2.10.1
IPython          : None
pandas_datareader: None
bs4              : 4.8.0
bottleneck       : None
fastparquet      : None
gcsfs            : None
lxml.etree       : 4.4.1
matplotlib       : None
numexpr          : None
odfpy            : None
openpyxl         : 2.5.14
pandas_gbq       : None
pyarrow          : None
pytables         : None
pytest           : 4.3.0
pyxlsb           : None
s3fs             : None
scipy            : 1.2.0
sqlalchemy       : None
tables           : None
tabulate         : None
xarray           : None
xlrd             : 1.2.0
xlwt             : None
xlsxwriter       : None
numba            : None

</details>
