#16 -- Clear previous commits

src/main/java/ru/ulstu/extractor/service/IndexService.java

@@ -48,6 +48,8 @@ public class IndexService {
             branchRepository.save(new Branch(repository, branchName));
         }
         List<Commit> commits = gitRepositoryService.getCommits(repositoryUrl, branchName);
+        commitRepository.deleteAll(branch.getCommits());
+        branch.getCommits().clear();
         branch.setCommits(commits);
         branchRepository.save(branch);
         gitRepositoryService.remove(repositoryUrl);