Stub Runner Boot fails to start due to missing class

we're adding the  dependency to stub runner

fixes #197

spring-cloud-contract-starters/spring-cloud-starter-contract-stub-runner/pom.xml

@@ -25,6 +25,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream-test-support</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-contract-wiremock</artifactId>