code: public void deleteProjectBadge(Serializable projectId, Integer badgeId) throws IOException {
          String tailUrl = GitlabProject.URL + "/" + sanitizeProjectId(projectId) + GitlabBadge.URL
                  + "/" + badgeId;
          retrieve().method(DELETE).to(tailUrl, Void.class);
      }
docs: Delete project badge
  
  @param projectId The id of the project for which the badge should be deleted
  @param badgeId   The id of the badge that should be deleted
  @throws IOException on GitLab API call error