Network Monitoring capability skeleton.
Merge branch 'develop' of https://github.com/dana-i2cat/opennaas into feature/sdnnet-monitoring-capab
NetworkStatistics class refactored and @Get annotation in method.
Merge branch 'feature/sdnnet-monitoring-capab' of github.com:adrian-rosello/opennaas into feature/sdnnet-monitoring-capab
Merge pull request #758 from adrian-rosello/feature/sdnnet-monitoring-capab

SDN-monitoring skeleton