Some improvement about branch management (#4756)

1. protect develop/master branch
2. disable merge buttion for pull request

.asf.yaml

@@ -0,0 +1,33 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+github:
+  labels:
+    - messaging
+    - streaming
+    - eventing
+    - cloud-native
+    - rocketmq
+    - java
+  enabled_merge_buttons:
+    # Enable squash button
+    squash: true
+    # Disable merge button
+    merge: false
+    # Enable rebase button
+    rebase: true
+  protected_branches:
+    master: {}
+    develop: {}