Tests

Add authentication credential callback support #128

Job	Run time
Build BlazingMQ as a dependency	15m 37s
Coverage	57s
Lint and Docs	40s
Test on Linux (3.11)	1m 7s
Test on Linux (3.13)	55s
Test on Linux (3.10)	1m 2s
Test on Linux (3.12)	58s
Test on Linux (3.9)	1m 2s
	22m 18s

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