New feature requests

[stanleybridge]

Nice work! At an initial glance, the first couple features I think would be great are:

1. ability to provide a JSON file to describe the format for test messages
   ...I realise of course that this would require all data types (including nested objects) to be parseable

2. Ability to specify different dicts and tie different field names to those dicts

3. Generate (separate or combined) random street address data... although this might be covered by feature (2) above.