* Adding SR-IOV capability discovery to node-feature-discovery
* SR-IOV capability discovery in NFD : code update after PR review
- using hostnetwork instead of volume mount in file node-feature-discovery-job.json.template
- iterating through network interfaces that are "up" in sources.go
- inserting logs in sources.go
- change in feature source name from "netid" to "network" in sources.go, README.md and main.go
* Added code for labels sriov=true (sriov_totalvfs > 0) and sriov-configured=true (sriov_numvfs > 0)
* Code Refactored: Added Network package and network.go
