Increase subnet & security group deletion timeout (2 -> 5 mins)

- this should prevent DependencyViolation errors while waiting for larger ASGs to shut down

builtin/providers/aws/resource_aws_security_group.go

@@ -295,7 +295,7 @@ func resourceAwsSecurityGroupDelete(d *schema.ResourceData, meta interface{}) er
 
 	log.Printf("[DEBUG] Security Group destroy: %v", d.Id())
 
-	return resource.Retry(2*time.Minute, func() error {
+	return resource.Retry(5*time.Minute, func() error {
 		_, err := conn.DeleteSecurityGroup(&ec2.DeleteSecurityGroupInput{
 			GroupID: aws.String(d.Id()),
 		})

builtin/providers/aws/resource_aws_subnet.go

@@ -166,7 +166,7 @@ func resourceAwsSubnetDelete(d *schema.ResourceData, meta interface{}) error {
 	wait := resource.StateChangeConf{
 		Pending:    []string{"pending"},
 		Target:     "destroyed",
-		Timeout:    2 * time.Minute,
+		Timeout:    5 * time.Minute,
 		MinTimeout: 1 * time.Second,
 		Refresh: func() (interface{}, string, error) {
 			_, err := conn.DeleteSubnet(req)