samples test should delete created VMs

[alexander-fenster]

Samples tests create VMs named asset-nodejs-* and they don't get deleted. Need to make sure the sample test deletes stale VMs.

./nodejs-asset/samples/test/sample.test.js:const bucketName = `asset-nodejs-${uuid.v4()}`;
./nodejs-asset/samples/test/sample.test.js:    instanceName = `asset-nodejs-${uuid.v4()}`;