Implementation of lighty.io as simulators (Step1)

It seems that it will be very difficult to migrate HoneyNode simulators to recent versions of ODL. This might be needed implementing OpenConfig models which are not well supported with current version. In this context, Lighty.io seems a reasonable candidate to provide emulators for OpenConfig. We shall evaluate if all function we need shall be supported, and the amount of work needed to build lighty.io based emulators.