ignore errors if 'ps aux' fails

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
Merge pull request #306 from ceph/wip-9024

ignore errors if 'ps aux' fails
Remove most ceph-specific tasks. They are in ceph-qa-suite now.

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Correctly find both internal and external tasks

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>