aws_s3_bucket: Fix can not use days = 0 with lifecycle transition.

[kjmkznr]

Add validate function in S3 bucket lifecycle's days attributes.

Put Bucket lifecycle

Type: Nonnegative Integer when used with Transition, Positive Integer when used with Expiration.

Test

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSS3Bucket_Lifecycle'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSS3Bucket_Lifecycle -timeout 120m
=== RUN   TestAccAWSS3Bucket_Lifecycle
--- PASS: TestAccAWSS3Bucket_Lifecycle (74.01s)
PASS
ok      github.com/terraform-providers/terraform-provider-aws/aws       74.026s

Fixes: #952

[radeksimko]

✅ relevant debug log (credit goes to @devonbleak )
✅ simplest fix
✅ relevant tests covering bugfix
✅ mentioned how to run those tests
✅ reasonable commit message, single commit

This is perfect PR & issue, pleasure to pull in, thanks @kjmkznr!

btw. In cases like this I tend to run all resource-level relevant acceptance tests, just to be on the safe side (i.e. all of S3 bucket), but they all pass anyway, so 👌

[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!