依赖：
A jar -> B jar
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.0</version>
<scope>test</scope>
</dependency>
Dependent range, dependent on the validity of
Each of a configuration dependency, the dependency of the range-dependent parameter determination scope, if there is no scope parameter defaults to compile dependent range
Dependence range:
