Specify osx_image to fix CI
Specify osx_image to fix CI

Signed-off-by: Fumiaki Matsushima <ac467387690ec79bffe461eb70db539cb2eb030a@gmail.com>

vdemeester/compose,dnephin/compose,thaJeztah/compose,thaJeztah/compose,shin-/compose,dnephin/compose,vdemeester/compose,funkyfuture/docker-compose,shin-/compose,funkyfuture/docker-compose