Add contributor information and licensing notice (#3433)
Add contributor information and licensing notice (#3433)

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arifogel/batfish,batfish/batfish,intentionet/batfish,intentionet/batfish,arifogel/batfish,batfish/batfish,intentionet/batfish,arifogel/batfish,intentionet/batfish,intentionet/batfish,dhalperi/batfish,batfish/batfish,dhalperi/batfish,dhalperi/batfish