- set the port to 8750, fixes gh-755
- stub runner app bases on thin jar, fixes gh-1385
a prerequisite for messaging support of docker images and polyglot messaging
While the previous approach did publish the contracts to local .m2 repository, it did not create the maven-metadata-local.xml file indicating a local release. It instead created maven-metadata.xml, which indicates a remote release. This wasn't issue when the stubs were retrieved by Gradle directly (in our flow we pre-check availability of these stubs by Gradle), it did however cause problems when they were being resolved by AetherStubDownloader used in SCC Stub Runner.
In addition, this newer implementation allows to enable any publish (remote or local) independently of each other, which wasn't the case previously.
Fixes#1283 - again
with this change we're adding generation of 2 docker images - verifier and stub runner
we also added a project `spring-cloud-contract-stub-runner-boot` which contains a far jar with stub runner boot
fixes gh-526, gh-516
