Exclude flow-build-info.json from generated .jar file (fixes #5)

Author: mlopezFC

pom.xml

@@ -149,7 +149,11 @@
                             <Vaadin-Package-Version>1</Vaadin-Package-Version>
                         </manifestEntries>
                     </archive>
-                </configuration>
+						<!-- Generated file that shouldn't be included in add-ons -->
+						<excludes>
+							<exclude>META-INF/VAADIN/config/flow-build-info.json</exclude>
+						</excludes>
+					</configuration>
             </plugin>
             <plugin>
                 <groupId>com.vaadin</groupId>