Highlight some of gnsq's features.
Block as expected on start, even if already started.
Don't store week reference to message_handler.
Test reader should raise runtime error if no handlers are registered on start.
Raise runtime error if starting the reader without a message handler.
Pass in noop message handler to suppress runtime error.
Better documentation for message signals.
Use cached property decorator connection pool.
Better documentation for nsqd signals.
Better reader signals documentation.
Add on_close signal to the reader.