Save image to S3 as a PNG file at /share/ endpoint

[anatoly-scherbakov]

Based on issue #3, we now need to actually save the PNG file onto S3 bucket and ensure the file indeed exists there. The boto3 library will be necessary for that.

    from mypy_boto3_s3 import ServiceResource as S3

    s3: S3 = boto3.Resource('s3')
    bucket = s3.Bucket(settings.S3_BUCKET_NAME)
    bucket.Object('...').upload_file(...)