get_archive puts the file in memory

## Long story short

When calling get_archive in containers.py, could you confirm that the whole file is stored in memory ?
If so with a large file, the machine could run out of memory.

What do you suggest to me if I want to get a stream to avoid storing the whole file in memory ?

## Your environment

aiodocker 0.19.1
python 3.8.6
Linux