tests: fix failure due to pytest deprecation
tests: fix failure due to pytest deprecation

Signed-off-by: Corentin Henry <f60a82830640bd3dc7c2c9859f7e03716ecb7ef8@gmail.com>

vdemeester/docker-py,funkyfuture/docker-py,vdemeester/docker-py,docker/docker-py,youhong316/docker-py,youhong316/docker-py,funkyfuture/docker-py,docker/docker-py