Allows users from govcloud and other regions (aws-cn) to now use the following resources correctly:
```
- data "aws_billing_service_account"
- data "aws_elb_service_account"
- resource "aws_cloudfront_origin_access_identity"
- resource "aws_ecs_service"
- resource "aws_iam_saml_provider"
- resource "aws_lambda_permission"
- resource "aws_sns_topic_policy"
```
* provider/aws: Support eu-west-2
This is the new London region - we don't have access yet but several
enquiries have come from customers who do.
* provider/aws: Support eu-west-2 region
* Update hosted_zones.go
