Upgrade to Vert.x 5.0.8

Author: vietj

pom.xml

@@ -14,7 +14,7 @@
   <version>1.0.0-SNAPSHOT</version>
 
   <properties>
-    <stack.version>5.0.0-SNAPSHOT</stack.version>
+    <stack.version>5.0.8</stack.version>
   </properties>
 
   <dependencyManagement>