Trove/Conductor-phase2

Description
Conductor service is designed to allocate backend access in one place.

Phase 1
Let guestagents speak with backend through conductor (Implemented).

Phase 2
Let taskamanager speak with backend through conductor (Not implemented yet).

Phase 3
Let API service speak with backend through conductor (Not implemented yet).

Justification
Conductor service is designed to allocate backend access in one place. All backend manipulation should be delegated to conductor.

Benefits
This feature would give an ability to secure its deployment since all services would speack only trough RPC and only one among them all would speak to database directly.

Impacts
From user/admin/deployer perspective nothig would change

Configuration
None

Database
None

Public API
No changes

CLI interface
No changes

ReST Part
No changes

Internal API

 * Extend conductor service API and manager to handle requests from taskmanager.

RPC API description
Will be defined during development

Guest Agent
No changes