SNS Message Attributes support for additional data types

[k-brooks]

Dependencies

None that I know of

Feature Request

Support String, String.Array, and Number data types in the messageAttributes argument of the snsPublish step. By opening the API against messageAttributes to accept a Map<String, Object> we can introspect the value class and map the corresponding AWS data type. Array/Set/List (any generic type) => String.Array Number => Number String or Undefined => String