use [jms-testkit] in JMS unit tests

[sullis]

No description provided.

[sullis]

ready for review

[sullis]

Ready for review.

[ennru]

Thank you for your suggestion to factor this out.

I'm a bit reluctant to pull in your library, though. I don't see a huge improvement for the Alpakka JMS tests and this change could easily be made in the tests without a new test depenency.

Can you explain why this needs to be in an external library?

[sullis]

This PR removes a significant amount of boilerplate code.

[jms-testkit] provides a concise API. The API was designed specifically for writing unit tests.

=> setting up an in-memory broker is 1 line: val broker = JmsBroker()
=> setting up an in-memory queue is 1 line: val queue = JmsQueue()
=> publishing a message is 1 line: queue.publishMessage("hello")
=> inspecting the contents of the queue is 1 line: queue.toSeq

Btw, [jms-testkit] is used by the [fs2-jms] library:

https://github.com/kiambogo/fs2-jms/blob/master/src/test/scala/ProducerSpec.scala#L32

[2m]

LGTM