Rule stubbing

This branch introduces methods on WireMockRule and WireMockClassRule for stubbing, delaying, and verifying. This makes using multiple WireMock rules within a test a little simpler, as there is no need to use WireMock.configureFor() to switch between instances.

e.g.

    @ClassRule
    public static WireMockClassRule firstService = new WireMockClassRule(9080);

    @ClassRule
    public static WireMockClassRule secondService = new WireMockClassRule(10080);

    @Test
    public void checkSomething() {
        firstService.stubFor(get(urlEqualTo("/things/4321"))
                .willReturn(aResponse().withStatus(404)))
        secondService.stubFor(put(urlEqualTo("/items/4321"))
                .willReturn(aResponse().withStatus(201)))

        runSomething();

        firstService.verify(getRequestedFor(urlEqualTo("/things/4321")));
        secondService.verify(0, putRequestedFor(urlMatching(".*")));
    }