bulkDeleteMessages doesn't seem to work properly

[jakemac53]

I ran into a couple issues with this method, the first one is a missing call to toList here, which gets things encoding to json properly.

After fixing that thoug I am getting a bad response exception. The body of the request looks right (serialized json array of ids), but the response is a 400 with this error {"_misc": ["Only dictionaries may be used in a DictType"]}.