Resource aws_route53_zone - count fix

[pawelsocha]

This PR solves #562.

Add domain name to caller reference to avoid generate non-unique id.
Add test with count parameter in aws_route53_zone resource.

Test results:

==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./... -v -run=TestAccAWSRoute53Zone_basic -timeout 120m
?   	github.com/terraform-providers/terraform-provider-aws	[no test files]
=== RUN   TestAccAWSRoute53Zone_basic
--- PASS: TestAccAWSRoute53Zone_basic (167.43s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	167.460s

Manual tests:

Before:

* aws_route53_zone.test[2]: 1 error(s) occurred:

* aws_route53_zone.test.2: HostedZoneAlreadyExists: A hosted zone has already been created with the specified caller reference.
	status code: 409, request id: cd51d304-4882-11e8-9b8e-4dcc7a507192

After:

Apply complete! Resources: 10 added, 0 changed, 0 destroyed.

[bflad]

Looks great @pawelsocha, thanks! 🚀

8 tests passed (all tests)
=== RUN   TestAccAWSRoute53Zone_importBasic
--- PASS: TestAccAWSRoute53Zone_importBasic (56.76s)
=== RUN   TestAccAWSRoute53Zone_updateComment
--- PASS: TestAccAWSRoute53Zone_updateComment (63.31s)
=== RUN   TestAccAWSRoute53Zone_private_basic
--- PASS: TestAccAWSRoute53Zone_private_basic (70.21s)
=== RUN   TestAccAWSRoute53Zone_private_region
--- PASS: TestAccAWSRoute53Zone_private_region (75.03s)
=== RUN   TestAccAWSRoute53ZoneAssociation_basic
--- PASS: TestAccAWSRoute53ZoneAssociation_basic (116.65s)
=== RUN   TestAccAWSRoute53Zone_basic
--- PASS: TestAccAWSRoute53Zone_basic (118.89s)
=== RUN   TestAccAWSRoute53ZoneAssociation_region
--- PASS: TestAccAWSRoute53ZoneAssociation_region (126.45s)
=== RUN   TestAccAWSRoute53Zone_forceDestroy
--- PASS: TestAccAWSRoute53Zone_forceDestroy (372.36s)

[bflad]

This has been released in version 1.17.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!