pybind: Fix aio_read handling of string buffer

Read data may contain \0, and buf.value interprerts them as string terminator.

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
pybind: rados.py code formatting and PEP8 fixes

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
pybind: rbd.py code formatting and PEP8 fixes

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
pybind: cephfs.py code formatting and PEP8 fixes

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
pybind: ceph_argparse.py code formatting and PEP8 fixes

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
pybind: ceph_rest_api.py code formatting and PEP8 fixes

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
python: ceph.in code formatting and PEP8 fixes

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
python: add PEP8 checks to make check

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>