Bumping up hadoop-yarn-server-router module to 3.0.0-beta1 post rebase.

(cherry picked from commit 69e3ed26809e12dd62cb66d258ef51c66db3be0a)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/pom.xml

@@ -19,7 +19,7 @@
   <parent>
     <artifactId>hadoop-yarn-server</artifactId>
     <groupId>org.apache.hadoop</groupId>
-    <version>3.0.0-alpha4-SNAPSHOT</version>
+    <version>3.0.0-beta1-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.apache.hadoop</groupId>