when I try to upload a large file, localstack basically freezes (and eventually times out).  
But if the file is all `1` bytes it succeeds.

succeeds:
```bash
aws s3 --endpoint-url=http://localhost:4572 mb s3://testbucket
python -c "print '\x01'*10000000" > testfile
echo $(ls -ahl | grep testfile)
aws s3 --endpoint-url=http://localhost:4572 cp testfile s3://testbucket/testfile
```

fails:
```bash
aws s3 --endpoint-url=http://localhost:4572 mb s3://testbucket
python -c "print 'a'*10000000" > testfile
echo $(ls -ahl | grep testfile)
aws s3 --endpoint-url=http://localhost:4572 cp testfile s3://testbucket/testfile
```
so, for me, both the file content and its size determine if this triggers or not. 
I'm using the latest version `0.9.5`
bucket_name = 'bucket-%s' % short_uid()
        self.s3_client.create_bucket(Bucket=bucket_name)
        rs = self.s3_client.list_object_versions(
            Bucket=bucket_name,
            EncodingType='url'
        )
        self.assertEqual(rs['ResponseMetadata']['HTTPStatusCode'], 200)
        self.assertEqual(rs['Name'], bucket_name)
        
        self._delete_bucket(bucket_name, [])
    
    
    
    def _create_test_queue(self):