- add t3.micro option

aws/README-zh.md

@@ -2,7 +2,7 @@
 
 # 使用 CloudFormation 在 Amazon EC2 上部署
 
-使用这个模板，你可以在 Amazon Elastic Compute Cloud（Amazon EC2）上快速搭建一个 IPsec VPN 服务器。在继续之前，请参见 EC2 [定价细节](https://aws.amazon.com/cn/ec2/pricing/on-demand/)。在部署中使用 `t2.micro` 服务器实例可能符合 [AWS 免费套餐](https://aws.amazon.com/cn/free/) 的资格。
+使用这个模板，你可以在 Amazon Elastic Compute Cloud（Amazon EC2）上快速搭建一个 IPsec VPN 服务器。在继续之前，请参见 EC2 [定价细节](https://aws.amazon.com/cn/ec2/pricing/on-demand/)。在部署中使用 `t2.micro` 或 `t3.micro` 服务器实例可能符合 [AWS 免费套餐](https://aws.amazon.com/cn/free/) 的资格。
 
 可用的自定义参数：
 

aws/README.md

@@ -2,7 +2,7 @@
 
 # Deploy to Amazon EC2 using CloudFormation
 
-This template will create a fully-working IPsec VPN server on Amazon Elastic Compute Cloud (Amazon EC2). Please make sure to check the EC2 [pricing details](https://aws.amazon.com/ec2/pricing/on-demand/) before continuing. Using a `t2.micro` server instance for your deployment may qualify for the [AWS Free Tier](https://aws.amazon.com/free/).
+This template will create a fully-working IPsec VPN server on Amazon Elastic Compute Cloud (Amazon EC2). Please make sure to check the EC2 [pricing details](https://aws.amazon.com/ec2/pricing/on-demand/) before continuing. Using a `t2.micro` or `t3.micro` server instance for your deployment may qualify for the [AWS Free Tier](https://aws.amazon.com/free/).
 
 Available customization parameters:
 

aws/cloudformation-template-ipsec.json

@@ -682,7 +682,7 @@
         },
         "InstanceType": {
             "Type": "String",
-            "Description": "The instance type of your VPN server. Using t2.micro may qualify for the AWS Free Tier.",
+            "Description": "The instance type of your VPN server. Using t2.micro or t3.micro may qualify for the AWS Free Tier.",
             "AllowedValues": [
                 "t2.micro",
                 "t3.nano",