Add Dockerfile

[alexvanin]

Tested in a local S3 Gateway deployment. Specify proper network if S3 Gateway runs in docker.

$ ls s3tests.conf
s3tests.conf

$ docker run   -v `pwd`/s3tests.conf:/s3-tests/s3tests.conf -e S3TEST_CONF=/s3-tests/s3tests.conf \
--network host -it s3-tests \
nosetests -v --nologcapture s3tests_boto3.functional

/usr/local/lib/python3.6/site-packages/boto3/compat.py:88: PythonDeprecationWarning: Boto3 will no 
longer support Python 3.6 starting May 30, 2022. To continue receiving service updates, bug fixes,
and security updates please upgrade to Python 3.7 or later. More information can be 
found here: https://aws.amazon.com/blogs/developer/python-support-policy-updates-for-aws-sdks-and-tools/
  warnings.warn(warning, PythonDeprecationWarning)
s3tests_boto3.functional.test_headers.test_object_create_bad_md5_invalid_short ... FAIL
s3tests_boto3.functional.test_headers.test_object_create_bad_md5_bad ... FAIL
...

[masterSplinter01]

I suppose it'd be better to place the text in NEOFS_README.md to avoid conflicts with the original ceph repository.

[alexvanin]

Agree, forgot about this file.