Add script to check package installability

The obs-installability script uses the dose-distcheck tool to check for package installability across the different images types.

It checks for the following group of packages lists:

target: for packages to be installed on minimal images hmi + target: for HMI packages to be installed on target images development + target: for tools used by OBS and developers sdk + development + target: for packages to be installed on basesdk images sdk + development + hmi + target: for packages to be installed on sdk images

And it translates the dose-distcheck YAML output to the JUnit format so that Jenkins can understand it.

This commit also includes the Dockerfile and Jenkisfile for integration.

Signed-off-by: Luis Araujo luis.araujo@collabora.co.uk