Allow template content to be fetched from configmap or env

[vishalsparmar]

The template for the Cloudformation yaml is currently inline string and difficult to maintain. Can we allow template to be fetched from config map or an env variable please. This will allow separating the stack yaml with cloud formation. Thanks

[cuppett]

You may want to check this out and see if it meets your needs:

https://github.com/cuppett/cloudformation-operator/pull/32