flink redis connector（支持flink sql）

1. 背景

1. 工作原因，需要基于flink sql做redis sink，但bahir 分支的flink connector支持只是基于datastream，而需要支持flink sql，还需要进一步完善
2. flink sql及flink table api按照flink官方社区，会是未来重点方向，包括python支持。因为所有的技术都会往使用友好方向发展，对外接口和使用友好，内部则会因为这个原因变得复杂起来。（但需要确定方向是否有误才行）

2. 步骤

1. 环境

1. jdk8
2. idea 2020
3. scala 2.11
4. pom

<packaging>jar</packaging>
<name>Flink Connector SnowDrop</name>

    <properties>
        <java.version>1.8</java.version>
        <flink.version>1.12.0</flink.version>
        <log4j.version>2.12.1</log4j.version>
        <scala.binary.version>2.11</scala.binary.version>
        <maven.compiler.source>${java.version}</maven.compiler.source>
        <maven.compiler.target>${java.version}</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <mongo.driver.version>3.8.2</mongo.driver.version>
        <fastjson.version>1.2.75</fastjson.version>
        <connector_redis>1.0</connector_redis>
    </properties>

    <repositories>
        <repository>
            <id>apache.snapshots</id>
            <name>Apache Development Snapshot Repository</name>
            <url>https://repository.apache.org/content/repositories/snapshots/</url>
            <releases>
                <enabled>false</enabled>
            </releases>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-java</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-table-api-java-bridge_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-connector-jdbc_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-walkthrough-common_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

        <!-- This dependency is provided, because it should not be packaged into the JAR file. -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-java_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-clients_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

     
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-table-api-scala-bridge_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
            <scope>provided</scope>
        </dependency>

       
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-table-planner_${scala.binary.version}</artifactId>
            <version>${flink.version}</