Could not load TestContextBootstrapper [null]

在对SpringBoot进行单元测试时，报错“Could not load TestContextBootstrapper [null]”

错误原因：

Maven的pom.xml中某些SpringBoot或Spring的依赖的版本有冲突

解决方法：

将冲突的依赖包版本修改为一致即可。

示例如下：

将SpringBoot的测试依赖包改为一致就可以了。

<dependencies>
    <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>1.5.7.RELEASE</version>
        </dependency>
               <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
            <version>1.5.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <version>1.5.7.RELEASE</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
            <version>1.5.7.RELEASE</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.3.12.RELEASE</version>
        </dependency>

    </dependencies>