Add a Dockerfile for building testing image
    
    With the image, you can run tests easily without installing
    many packages.
    
    Build the image and run:
    podman build -t odcs-test -f Dockerfile-test .
    podman run --rm odcs-test
    
    or
    podman run --rm -v .:/src:Z quay.io/exd-guild-compose/odcs-test
    
    JIRA: RHELCMP-4580
    Signed-off-by: Haibo Lin <hlin@redhat.com>