Add support for GovCloud region

Author: Michael MacDonald

aws_region.go

@@ -8,6 +8,7 @@ const (
 	AWS_REGION_US_EAST_1      AWSRegion = "us-east-1"
 	AWS_REGION_US_WEST_1      AWSRegion = "us-west-1"
 	AWS_REGION_US_WEST_2      AWSRegion = "us-west-2"
+	AWS_REGION_US_GOV_WEST_1  AWSRegion = "us-gov-west-1"
 	AWS_REGION_EU_WEST_1      AWSRegion = "eu-west-1"
 	AWS_REGION_EU_CENTRAL_1   AWSRegion = "eu-central-1"
 	AWS_REGION_AP_SOUTHEAST_1 AWSRegion = "ap-southeast-1"
@@ -20,6 +21,7 @@ var AWSRegions = []AWSRegion{
 	AWS_REGION_US_EAST_1,
 	AWS_REGION_US_WEST_1,
 	AWS_REGION_US_WEST_2,
+	AWS_REGION_US_GOV_WEST_1,
 	AWS_REGION_EU_WEST_1,
 	AWS_REGION_EU_CENTRAL_1,
 	AWS_REGION_AP_SOUTHEAST_1,
@@ -44,7 +46,7 @@ func (r AWSRegion) Validate() error {
 		return ErrAWSRegionEmptyString
 	}
 
-	if r != AWS_REGION_US_EAST_1 && r != AWS_REGION_US_WEST_1 && r != AWS_REGION_US_WEST_2 &&
+	if r != AWS_REGION_US_EAST_1 && r != AWS_REGION_US_WEST_1 && r != AWS_REGION_US_WEST_2 && r != AWS_REGION_US_GOV_WEST_1 &&
 		r != AWS_REGION_EU_WEST_1 && r != AWS_REGION_EU_CENTRAL_1 &&
 		r != AWS_REGION_AP_SOUTHEAST_1 && r != AWS_REGION_AP_SOUTHEAST_2 && r != AWS_REGION_AP_NORTHEAST_1 &&
 		r != AWS_REGION_SA_EAST_1 {