tests: port TestAllocRunner_RetryArtifact
tests: port TestAllocRunner_RetryArtifact

Port TestAllocRunner_RetryArtifact from https://github.com/hashicorp/nomad/blob/v0.8.7/client/alloc_runner_test.go#L610-L672

I changed the test name because it doesn't actually test that artifact
hooks is retried

hashicorp/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,burdandrei/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,dvusboy/nomad,burdandrei/nomad,hashicorp/nomad,burdandrei/nomad