Merged in dev/gideon/terraform_cluster_v1.1_2020.10.30 (pull request e…

…lastic#16)

* Update cluster terraform for "v1.1"

Moved Engageli code to a separate instance so it's easier to manually scale
up/down the number of ant-media instances.

Instances are automatically provisioned with 3rd party code. Only Engageli
instance needs another script to be run after deployment is complete to setup
the Engageli services and webapps.

Create media-manager buckets.

Create initial route53 entries.

By default create two sandboxes: class and staging.

Minor change to fabfile to support adding a user to any instance type, change
ant-media sandbox config to use stun, and support clean install of certbot.

Approved-by: Hussain Kader

aws/ams-all-in-one-tf/main.tf

@@ -185,7 +185,7 @@ resource "aws_s3_bucket" "mm" {
 
   cors_rule {
     # allowed_headers = ["*"]
-    allowed_methods = ["GET"]
+    allowed_methods = ["GET", "HEAD"]
     allowed_origins = ["https://*.engageli.com"]
     # expose_headers  = ["ETag"]
     # max_age_seconds = 3000