Incorrect ValueError: AllowedPattern can only be used with parameters of the String type

[akarve]

Example:

    cft.add_parameter(
        Parameter(
            "Foo",
            Type="CommaDelimitedList",
            AllowedPattern="^[A-Z]{2}$",
            Default="",
        )
    )

According to the AWS docs this should be allowed:

AllowedPattern
A regular expression that represents the patterns to allow for String or CommaDelimitedList types. When applied on a parameter of type String, the pattern must match the entire parameter value provided. When applied to a parameter of type CommaDelimitedList, the pattern must match each value in the list.