provider/aws: Update KMS Alias acceptance tests
provider/aws: Update KMS Alias acceptance tests

Updates KMS tests to ensure compatibility with running our tests in parallel

```
$ make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSKmsAlias_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/02/09 09:43:42 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSKmsAlias_ -timeout 120m
=== RUN   TestAccAWSKmsAlias_basic
--- PASS: TestAccAWSKmsAlias_basic (51.63s)
=== RUN   TestAccAWSKmsAlias_name_prefix
--- PASS: TestAccAWSKmsAlias_name_prefix (39.58s)
=== RUN   TestAccAWSKmsAlias_no_name
--- PASS: TestAccAWSKmsAlias_no_name (42.27s)
=== RUN   TestAccAWSKmsAlias_multiple
--- PASS: TestAccAWSKmsAlias_multiple (40.04s)
PASS
ok      github.com/hashicorp/terraform/builtin/providers/aws    173.547s
```

terraform-providers/terraform-provider-aws,nbaztec/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,nbaztec/terraform-provider-aws,kjmkznr/terraform-provider-aws,ashinohara/terraform-provider-aws,nbaztec/terraform-provider-aws,ClementCunin/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,kjmkznr/terraform-provider-aws,Ninir/terraform-provider-aws,Ninir/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,nbaztec/terraform-provider-aws,ashinohara/terraform-provider-aws,terraform-providers/terraform-provider-aws,ClementCunin/terraform-provider-aws,Ninir/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,kjmkznr/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,Ninir/terraform-provider-aws,ClementCunin/terraform-provider-aws,ClementCunin/terraform-provider-aws,ashinohara/terraform-provider-aws,ashinohara/terraform-provider-aws,terraform-providers/terraform-provider-aws