Test to ensure credential definition is defined after index.registerType
Avoid corrupting message payload while logging.
Add more tests for function node.
Test Node send for req/res behaviour.
Test Node status method.
Adding unit tests for credentials.extract
Add webSocketKeepAliveTime setting to aid testing.
Add comms keep alive tests.
Remove redundant assignment.

The publish immediately overwrites this time so there isn't much
point setting it.