Develop PI Web API Client

[poorva1209]

• This will be used inside Pi_service (as simulation output) to publish data to Field Bus Manager.

Pi_service:

• use the web client API to access Pi data
• convert Pi measurements format to CIM
• will publish measurements for the whole network to the field bus manager
• field bus manager divides and publishes it to individual areas

[AAndersn]

Nov 28: Able to read and post data from Linux node. Using Rest API (not SDK).