The spring context now fails to start if the stub cannot be found

The spring context now fails to start if the stub cannot be found, enabling the test to fail as quickly as possible for feedback

spring-cloud-contract-stub-runner/src/main/java/org/springframework/cloud/contract/stubrunner/AetherStubDownloader.java

@@ -197,7 +197,7 @@ public class AetherStubDownloader implements StubDownloader {
 			throw new IllegalStateException("Cannot resolve version range", e);
 		}
 		if (rangeResult.getHighestVersion() == null) {
-			log.error("For groupId [" + stubsGroup + "] artifactId [" + stubsModule + "] "
+			throw new IllegalArgumentException("For groupId [" + stubsGroup + "] artifactId [" + stubsModule + "] "
 					+ "and classifier [" + classifier + "] the version was not resolved!");
 		}
 		return rangeResult.getHighestVersion() == null ? null : rangeResult.getHighestVersion().toString();