Fix CodeDeploy sample to work in gov-cloud (#609)

**Why?**

At the moment, the install script for CodeDeploy would install CodeDeploy using
the global S3 URL to fetch the file from the S3 bucket.

As such:
```
https://aws-codedeploy-${REGION}.s3.amazonaws.com/latest/install
```

However, the CodeDeploy Gov cloud buckets are not available through this
global URL. So when the REGION=`us-gov-east-1` or `us-gov-west-1` it would
fail.

**What?**

To fix this, we should use the regional URL instead:

```
https://aws-codedeploy-${REGION}.s3.${REGION}.amazonaws.com/latest/install
```

samples/sample-ec2-with-codedeploy/scripts/install-codedeploy.sh

@@ -36,7 +36,7 @@ function platformize(){
 function execute(){
   if [ ${PLAT} = "ubuntu" ]; then
     cd /tmp/
-    wget https://aws-codedeploy-${REGION}.s3.amazonaws.com/latest/install
+    wget https://aws-codedeploy-${REGION}.s3.${REGION}.amazonaws.com/latest/install
     chmod +x ./install
 
     if ./install auto; then
@@ -56,7 +56,7 @@ function execute(){
 
   elif [ ${PLAT} = "amz" ]; then
     cd /tmp/
-    wget https://aws-codedeploy-${REGION}.s3.amazonaws.com/latest/install
+    wget https://aws-codedeploy-${REGION}.s3.${REGION}.amazonaws.com/latest/install
     chmod +x ./install
 
     if ./install auto; then