Fix commons-lang missing dependency

Author: acocuzzo

samples/snippets/pom.xml

@@ -85,6 +85,11 @@
       <version>1.1.3</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+     <groupId>org.apache.commons</groupId>
+     <artifactId>commons-lang3</artifactId>
+     <version>3.12</version>
+    </dependency>
   </dependencies>
 
 </project>

samples/snippets/src/test/java/pubsublite/spark/SampleTestBase.java

@@ -43,7 +43,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
-import org.apache.commons.lang.StringUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.maven.shared.invoker.DefaultInvocationRequest;
 import org.apache.maven.shared.invoker.DefaultInvoker;
 import org.apache.maven.shared.invoker.InvocationOutputHandler;