Test remote PDU with BBB & iw20gm

Issue Background

Boards such as the iw20gm requires hard power control (soft reboot not suitable) for power cycling during lava tests. b@d needs to be tests for the supported boards.

Issue description

Using http://www.aviosys.com/9258st.html (remote pdu, with 'ping' addressable power) as known working model, jinja files for boards need to be tested with commands for on, off & reboot. In this case using curl for http requests to the pdu. This also allows for boards to be tested from an off state.

Acceptance criteria

No change in testing outcome