ECS Entrypoint as a CommaDelimitedList

With AWS CloudFormation I know that we can supply a CommaDelimitedList parameter for the EntryPoint property when setting up the ContainerDefinition. When I try to do the same thing using this library I get the error ```Attribute EntryPoint must be a list.```

Looking at the source I see that it is expecting a list of strings. So clearly it is doing what it is supposed to do.

Just making sure I am not missing anything here. I can easily convert my parameter to a list of strings.