docs: 19.0.0 libraries-bom (#1312)

@suztomo

Author: elharo

docs/setup.md

@@ -23,7 +23,7 @@ the `dependencyManagement` section of your `pom.xml`:
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>18.0.0</version>
+      <version>19.0.0</version>
       <type>pom</type>
       <scope>import</scope>
      </dependency>