FakeFileWrapper didn't implement __next__

[mlouielu]

Describe the bug

FakeFileWrapper didn't implement __next__

How To Reproduce

• next(f)

raise:

        with open(input_fn) as f:
>           student_ids = next(f).strip().split(',')
E           TypeError: 'FakeFileWrapper' object is not an iterator

Your enviroment
Please run the following and paste the output.

python -c "import platform; print(platform.platform())"
python -c "import sys; print('Python', sys.version)"
python -c "from pyfakefs.fake_filesystem import __version__; print('pyfakefs', __version__)"

Linux-4.20.0-rc1-x86_64-with-arch
Python 3.7.3 (default, May  3 2019, 11:10:59) 
[GCC 8.2.1 20181127]
pyfakefs 3.6

[mrbean-bremen]

Thanks - good catch!