Maintain node_id as attribute for manager

[shtripat]

This is required while processing a job from the job queue. If the current node's id falls within the list of node_ids passed as parameters, the job would be picked and processed by that node. Only one node would pick and process the job from the list of node_ids passed in parameter for job.

[shtripat]

In the context of Tendrl/specifications#102

[shtripat]

Not required