DEVPROD-5097: Prevent deploy_to_prod task from failing silently (ever…

…green-ci#2274)

scripts/deploy/deploy.sh

@@ -1,8 +1,12 @@
-#!/bin/sh
+#!/bin/bash
 
-# This script runs the aws cli command to deploy the app to s3
+# This script runs the AWS CLI command to deploy the app to S3.
 
-# Try this step and throw an error if it fails
 echo "Deploying to S3"
-aws s3 sync build/ s3://"${BUCKET}"/ --acl public-read --follow-symlinks --delete --exclude .env-cmdrc.json 
-echo "Deployed to S3"
+
+if ! aws s3 sync build/ s3://"${BUCKET}"/ --acl public-read --follow-symlinks --delete --exclude .env-cmdrc.json; then
+  echo "Deployment to S3 failed"
+  exit 1
+else
+  echo "Successfully deployed to S3"
+fi