build: set vaadin dependency to 14.11.13

Author: javier-godoy

pom.xml

@@ -9,7 +9,7 @@
 	<description>Image Comparison Slider Add-on for Vaadin Flow</description>
 
 	<properties>
-		<vaadin.version>14.7.7</vaadin.version>
+		<vaadin.version>14.11.13</vaadin.version>
 		<maven.compiler.source>1.8</maven.compiler.source>
 		<maven.compiler.target>1.8</maven.compiler.target>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>