provider/aws: Remove delete retention on CloudFront tests

To play better with Travis and not bloat the test account with disabled
distributions. Anyone working on testing the resource can manually
re-enable this setting to ensure tests finish in a timely manner.

builtin/providers/aws/resource_aws_cloudfront_distribution_test.go

@@ -179,7 +179,6 @@ resource "aws_cloudfront_distribution" "s3_distribution" {
 	viewer_certificate {
 		cloudfront_default_certificate = true
 	}
-	retain_on_delete = true
 }
 `, rand.New(rand.NewSource(time.Now().UnixNano())).Int())
 
@@ -234,7 +233,6 @@ resource "aws_cloudfront_distribution" "custom_distribution" {
 	viewer_certificate {
 		cloudfront_default_certificate = true
 	}
-	retain_on_delete = true
 }
 `, rand.New(rand.NewSource(time.Now().UnixNano())).Int())
 
@@ -336,7 +334,6 @@ resource "aws_cloudfront_distribution" "multi_origin_distribution" {
 	viewer_certificate {
 		cloudfront_default_certificate = true
 	}
-	retain_on_delete = true
 }
 `, rand.New(rand.NewSource(time.Now().UnixNano())).Int())
 
@@ -383,6 +380,5 @@ resource "aws_cloudfront_distribution" "no_optional_items" {
 	viewer_certificate {
 		cloudfront_default_certificate = true
 	}
-	retain_on_delete = true
 }
 `, rand.New(rand.NewSource(time.Now().UnixNano())).Int())