Release 0.55.1

This release drops support for publishing bytes values via Plugin.publish.

Though this was technically allowed by pywaggle before, the node data pipeline would silently drop messages with bytes data leading to confusion on for the end user.

In the future, we may change our position on this but our current recommendation is to either:

1. Unpack binary data into individual int, float or string fields.
2. Manage your own serialization and deserialization scheme.