Update liferay dependency to 6.2.5

Official Liferay support for FW 8 is 6.2.

pom.xml

@@ -23,7 +23,7 @@
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 
         <!-- Used version numbers for dependencies -->
-        <liferay.portal.version>6.0.2</liferay.portal.version>
+        <liferay.portal-service.version>6.2.5</liferay.portal-service.version>
         <jetty.version>9.3.9.v20160517</jetty.version>
 
         <vaadin.gwt.version>2.8.0</vaadin.gwt.version>

server/pom.xml

@@ -21,7 +21,7 @@
         <dependency>
             <groupId>com.liferay.portal</groupId>
             <artifactId>portal-service</artifactId>
-            <version>${liferay.portal.version}</version>
+            <version>${liferay.portal-service.version}</version>
             <scope>provided</scope>
         </dependency>