Remove referenceless enum

hippo4j-spring-boot/hippo4j-config-spring-boot-starter/src/main/java/cn/hippo4j/config/springboot/starter/common/ConfigFileTypeEnum.java

@@ -1,64 +0,0 @@
-/*
- * 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.
- */
-
-package cn.hippo4j.config.springboot.starter.common;
-
-/**
- * Config file type enum.
- */
-public enum ConfigFileTypeEnum {
-
-    /**
-     * PROPERTIES
-     */
-    PROPERTIES {
-
-        @Override
-        public String type() {
-            return "properties";
-        }
-    },
-
-    /***
-     * YML
-     */
-    YML {
-
-        @Override
-        public String type() {
-            return "yml";
-        }
-    },
-
-    /***
-     * YAML
-     */
-    YAML {
-
-        @Override
-        public String type() {
-            return "yaml";
-        }
-    };
-
-    /**
-     * Type.
-     *
-     * @return
-     */
-    public abstract String type();
-}