code: public void createBranch(Serializable projectId, String branchName, String ref) throws IOException {
          String tailUrl = GitlabProject.URL + "/" + sanitizeProjectId(projectId) + GitlabBranch.URL;
          dispatch().with("branch", branchName).with("ref", ref).to(tailUrl, Void.class);
      }
docs: Create Branch.
  <a href="http://doc.gitlab.com/ce/api/branches.html#create-repository-branch">
  Create Repository Branch Documentation
  </a>
  
  @param projectId  The id of the project
  @param branchName The name of the branch to create
  @param ref        The branch name or commit SHA to create branch from
  @throws IOException on gitlab api call error