Implement version 2 payload with more hw info

Bumping the payload version to two, and adding CPU, Memory, and Block
Device information to the inventory.

Added dependency on psutil for available memory and cpu_count.
Requirements line copied from global requirements

Change-Id: Ia39c85c91b1d60468667787a7978020084dc6c2a
Merge "Implement version 2 payload with more hw info"