From your GitHub home's mule-aggregators-module folder, build the module with
mvn clean install
This will install the module to your local Maven repository, and also generate the plugin file, tests, etc.
Add this dependency to your Mule application's pom.xml
<dependency>
<groupId>org.mule.modules</groupId>
<artifactId>mule-aggregators-module</artifactId>
<version>1.1.0-SNAPSHOT</version>
<classifier>mule-plugin</classifier>
</dependency>