aws_tag_deprovision: continue on s3tag fetch

There might be s3buckets in account that attached to different region.
This caused the deprovisioner to fail fataly.
For example:
2018/09/24 22:52:43 DEBUG: Request s3/GetBucketTagging Details:
---[ REQUEST POST-SIGN ]-----------------------------
GET /?tagging= HTTP/1.1
Host: atectonic-demo-97d9f36d6647e7be86e0ce5baca4e419.s3.amazonaws.com
User-Agent: aws-sdk-go/1.15.41 (go1.10.3; linux; amd64)
Authorization: <redacted>
Accept-Encoding: gzip

---[ RESPONSE ]--------------------------------------
HTTP/1.1 400 Bad Request
Connection: close
Transfer-Encoding: chunked
Content-Type: application/xml
Date: Tue, 25 Sep 2018 05:55:26 GMT
Server: AmazonS3

-----------------------------------------------------
2018/09/24 22:55:27 <?xml version="1.0" encoding="UTF-8"?>
<Error><Code>AuthorizationHeaderMalformed</Code><Message>The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'us-west-2'</Message><Region>us-west-2</Region></Error>

Skipping errors allows us to create best possible list of s3 buckets
that might have the required tag.

contrib/pkg/aws_tag_deprovision/aws_tag_deprovision.go

@@ -25,7 +25,6 @@ import (
  "k8s.io/apimachinery/pkg/util/wait"
 
  "github.com/aws/aws-sdk-go/aws"
- "github.com/aws/aws-sdk-go/aws/awserr"
  "github.com/aws/aws-sdk-go/aws/session"
  "github.com/aws/aws-sdk-go/service/autoscaling"
  "github.com/aws/aws-sdk-go/service/ec2"
@@ -973,26 +972,16 @@ func deleteSubnets(session *session.Session, filter awsFilter, logger log.FieldL
 }
 
 // bucketsToAWSObjects will convert a list of S3 Buckets to awsObjectsWithTags (for easier filtering)
-func bucketsToAWSObjects(buckets []*s3.Bucket, s3Client *s3.S3) ([]awsObjectWithTags, error) {
+func bucketsToAWSObjects(buckets []*s3.Bucket, s3Client *s3.S3, logger log.FieldLogger) ([]awsObjectWithTags, error) {
  bucketObjects := []awsObjectWithTags{}
 
  for _, bucket := range buckets {
  tags, err := s3Client.GetBucketTagging(&s3.GetBucketTaggingInput{
  Bucket: bucket.Name,
  })
  if err != nil {
- if aerr, ok := err.(awserr.Error); ok {
- switch aerr.Code() {
- case "NoSuchTagSet":
- // it is okay for a bucket to have no tags, just ignore it
- // since we can't filter on a tagless bucket
- continue
- default:
- return bucketObjects, err
- }
- } else {
- return bucketObjects, err
- }
+ logger.Errorf("error getting tags for bucket %s: %v, skipping...", bucket.Name, err)
+ continue
  }
 
  tagsAsMap, err := tagsToMap(tags.TagSet)
@@ -1060,7 +1049,7 @@ func deleteS3Buckets(session *session.Session, filter awsFilter, logger log.Fiel
  return false, nil
  }
 
- awsObjects, err := bucketsToAWSObjects(results.Buckets, s3Client)
+ awsObjects, err := bucketsToAWSObjects(results.Buckets, s3Client, logger)
  if err != nil {
  return false, fmt.Errorf("error converting buckets to internal objects: %v", err)
  }