fix missing gfind in travis build script
fix missing gfind in travis build script

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