Remove spring-cloud-contract-wiremock dependency

The preferred way of adding `spring-cloud-contract-wiremock` is via
`spring-cloud-starter-stub-runner`. It has always included that
dependency, and we want to limit the number of starters.

See gh-629

initializr-service/src/main/resources/application.yml

@@ -1030,18 +1030,11 @@ initializr:
           starter: false
         - name: Cloud Contract Stub Runner
           id: cloud-contract-stub-runner
-          description: Stub Runner for HTTP/Messaging based communication
+          description: Stub Runner for HTTP/Messaging based communication, allows creating WireMock stubs from RestDocs tests
           groupId: org.springframework.cloud
           artifactId: spring-cloud-starter-contract-stub-runner
           scope: test
           starter: false
-        - name: Cloud Contract WireMock
-          id: cloud-contract-wiremock
-          description: Test dependencies required for the WireMock HTTP server
-          groupId: org.springframework.cloud
-          artifactId: spring-cloud-contract-wiremock
-          scope: test
-          starter: false
     - name: Pivotal Cloud Foundry
       bom: spring-cloud-services
       versionRange: "[1.3.0.RELEASE,2.0.0.M1)"