Documentation update.

Author: virgofx

README.md

@@ -137,6 +137,7 @@ This may be best for first time users with
             "Effect": "Allow",
             "Action": [
                 "codedeploy:CreateDeployment",
+                "codedeploy:CreateDeploymentGroup",
                 "codedeploy:GetDeployment",
                 "codedeploy:GetDeploymentGroup",
                 "codedeploy:GetDeploymentInstance",
@@ -237,6 +238,12 @@ Environment Variables:
 
 * `AWS_CODE_DEPLOY_AUTO_SCALING_GROUPS` (optional): Auto Scaling groups when creating a deployment group
 
+Required IAM Access:
+```
+    "codedeploy:CreateDeploymentGroup",
+    "codedeploy:GetDeploymentGroup"
+```
+
 #### Step 6: Compressing Source
 
 This step compresses the specified source directory as a zip file in preparation for uploading to S3. This is useful for application deployments that use unique file names per revision. This helps limit the transfer to and from S3 during deployment.