Problem when retrieving the jar file of GTFS realtime validator

Dear all,

I want to watch a realtime GTFS flux over a couple of hours,

I landed on this page:

But I am stuck at the deployment:

pom.xml:
<dependency>
  <groupId>org.mobilitydata</groupId>
  <artifactId>gtfs-realtime-validator-webapp</artifactId>
  <version>1.0.0-SNAPSHOT</version>
</dependency>

mvn install

does not retrieve the jar file. Am I missing something?

regards,

Xavier