Added IgnoreWireMockRule annotation

I'm using WireMock a lot recently and I really like the way a JUnit Rule could be created to automatically spin up a WireMock server.

Some of the tests I'm working on require the server not to be running, i.e. testing what happens when downstream services are unreachable. 

Instead of using a programmatic approach to start/stop the WireMock server, I thought an annotation could be useful. If you annotate a test with ```@IgnoreWireMockRule```, the ```apply()``` method will prevent starting the server. 

As part of that, I also removed implementing a deprecated interface. Hope this is helpful.