private RepositoryInfo repoInfo(String repoName, String repoVersion, String url, String osType) {
    RepositoryInfo info = new RepositoryInfo();
    info.setRepoId(String.format("%s:%s", repoName, repoVersion));
    info.setRepoName(repoName);
    info.setBaseUrl(url);
    info.setOsType(osType);
    return info;
  }
If two add-on services define the same repo, the repo should be disregarded.
This applies per os, so the same repo can be defined for multiple os'es (e.g redhat5 and redhat6)
@throws Exception
ambari-server/src/test/java/org/apache/ambari/server/stack/StackModuleTest.java