Specify target jobs instead of profiles?

[adarlan]

Instead of implement profiles, it's better to implement an option to specify the target jobs.
Plankton will only run the target jobs and the jobs they depends on, directly or indirectly.

When all of the target jobs have a final status,
any other service/job running is stopped.

The pipeline succeeds only if all of the target jobs succeed.
The final status of any other job does not matter.

If no target job is specified,
all the jobs are considered target jobs.

If a job is a dependency for other jobs with the condition service_healthy or service_started,
it can not be defined as target job.
It will always be stopped when no more jobs depends on it based on these conditions.