Add private jobs flag to jobs
- Added a migration file to add is_privatefield tojobswith default value beingfalse.
- Added a not_privatescope tojob.rband chained it withstatus_onandJob.pendingso that status pages does not includeprivate jobs.
- Chanined not_privatescope withJob.historyso that package history pages do not includeprivate jobs.
- Added is_private: falseto query in GET/:user/jobs/?if unauthorized user or job history is not of logged in user so that private jobs are visible to users who created them.
- Added/Updated tests in spec/debcifor the above.
Edited  by Pavit Kaur