Added release train shortcut for args

releaser-spring/src/main/java/releaser/internal/spring/Arguments.java

@@ -140,4 +140,7 @@ public final class Arguments implements Serializable {
 				.collect(Collectors.toCollection(LinkedList::new));
 	}
 
+	public ProjectVersion releaseTrain() {
+		return this.projects.releaseTrain(this.properties);
+	}
 }