Fixes the `TestAccAWSAutoscalingLifecycleHook_omitDefaultResult` acceptance test to run in parallel.
```
$ make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSAutoscalingLifecycleHook_omitDefaultResult'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/02/15 22:33:26 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSAutoscalingLifecycleHook_omitDefaultResult -timeout 120m
=== RUN TestAccAWSAutoscalingLifecycleHook_omitDefaultResult
--- PASS: TestAccAWSAutoscalingLifecycleHook_omitDefaultResult (146.91s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/aws 146.917s
```