make test more robust
make test more robust

MetacoSA/NBitcoin,HermanSchoenfeld/NBitcoin,dangershony/NStratis,NicolasDorier/NBitcoin,MetacoSA/NBitcoin,stratisproject/NStratis,lontivero/NBitcoin,thepunctuatedhorizon/BrickCoinAlpha.0.0.1