Adding option to dump mappings to files (#356)

without this feature we're missing an option to print all mappings registered for servers
with this feature it will be much easier to debug what was registered in which http server stub. The mappings will be dumped to files with name artifactName_registeredPort

fixes #355

docs/src/main/asciidoc/migrations.adoc

@@ -0,0 +1,19 @@
+:core_path: ../../../..
+:doc_samples: {core_path}/samples/wiremock-jetty
+:wiremock_tests: {core_path}/spring-cloud-contract-wiremock
+
+In the following document we will write about necessary migration steps between versions.
+
+=== 1.0.x -> 1.1.x
+
+TODO: https://github.com/spring-cloud/spring-cloud-contract/issues/350
+
+=== 1.1.x -> 1.2.x
+
+==== Custom `HttpServerStub`
+
+By introducing a method `String registeredMappings()` in the public interface
+`HttpServerStub`, if you wrote a custom `HttpServerStub` implementation, you'll
+have to implement that method too. It should return a `String` representing
+all mappings available in a single `HttpServerStub`. Related to
+https://github.com/spring-cloud/spring-cloud-contract/issues/355[issue 355].

docs/src/main/asciidoc/spring-cloud-contract.adoc

@@ -23,3 +23,7 @@ include::verifier/spring-cloud-contract-verifier.adoc[]
 == Spring Cloud Contract WireMock
 
 include::spring-cloud-wiremock.adoc[]
+
+== Migrations
+
+include::migrations.adoc[]

docs/src/main/asciidoc/verifier/introduction.adoc

@@ -868,6 +868,12 @@ The generated tests all boil down to RestAssured in some form or fashion which r
 logging.level.org.apache.http.wire=DEBUG
 ----
 
+==== How can I see what got registered in the HTTP server stub?
+
+You can use the `mappingsOutputFolder` property on `@AutoConfigureStubRunner` or `StubRunnerRule`
+to dump all mappings per artifact id. Also the port at which the given stub server was
+started will be attached.
+
 ==== Can I reference the request from the response?
 
 Yes! With version 1.1.0 we've added such a possibility. On the HTTP stub server side we're providing support