add volume populate tests

[bergwolf]

 ✘ ⚡  /go/src/github.com/hyperhq/hypercli/integration-cli   populate-test  go test
finish init
INFO: Testing against a remote daemon(tcp://147.75.195.37:6443)
[2016-09-13 07:09:52] github.com/hyperhq/hypercli/integration-cli.(*DockerSuite).TestPopulateImageVolume - 107.396555 sec
[2016-09-13 07:12:07] github.com/hyperhq/hypercli/integration-cli.(*DockerSuite).TestPopulateImplicitVolume - 22.246503 sec
[2016-09-13 07:12:46] github.com/hyperhq/hypercli/integration-cli.(*DockerSuite).TestPopulateMultiMountImplicitVolume - 27.165430 sec
[2016-09-13 07:13:30] github.com/hyperhq/hypercli/integration-cli.(*DockerSuite).TestPopulateMultiMountNamedVolume - 25.806369 sec
[2016-09-13 07:14:14] github.com/hyperhq/hypercli/integration-cli.(*DockerSuite).TestPopulateNamedImageVolume - 80.185182 sec
[2016-09-13 07:15:59] github.com/hyperhq/hypercli/integration-cli.(*DockerSuite).TestPopulateNamedVolume - 28.354653 sec
OK: 6 passed
PASS
ok      github.com/hyperhq/hypercli/integration-cli     424.072s