Consider "what ifs" for unit tests with Wiremock

[stevewalton28]

 * What could go wrong?
 *  - what happens if connection is not established
 *  - what happens if connection is lost halfway through?
 *  - what happens if connection is successful?
 *  - what happens if the cast fails in getTotalDeadLetterQueueSize()?
 *  - what happens if

ArtemisJolokiaClientTests