hub4j#1967 Adding rename method

Author: sbouchexbellomie-Philips

src/main/java/org/kohsuke/github/GHBranch.java

@@ -192,6 +192,19 @@ public GHCommit merge(String head, String commitMessage) throws IOException {
         return result;
     }
 
+    /**
+     * Rename this branch.
+     *
+     * @param name
+     *            the name
+     * @throws IOException
+     *             the io exception
+     */
+    @CheckForNull
+    public void rename(String name) throws IOException {
+        root().createRequest().method("POST").with("new_name", name).withUrlPath(getApiRoute() + "/rename").send();
+    }
+
     /**
      * Gets the api route.
      *