add flow-react dependency for maven plugin integration tests

Author: mcollovati

flow-plugins/flow-maven-plugin/pom.xml

@@ -71,6 +71,12 @@
             <artifactId>flow-polymer2lit</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>flow-react</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <!-- Needed for lambdas in Mojos -->