Simplify build and add build of armv8 image

.travis.yml

@@ -5,9 +5,6 @@ sudo: required
 services:
     - docker
 
-script:
-    - mvn package
-
 after_success:
   - docker login  -u $DOCKER_LOGIN -p $DOCKER_PASSWORD
   - if [ "$TRAVIS_BRANCH" == "master" ]; then
@@ -20,4 +17,7 @@ after_success:
     docker push plantuml/plantuml-server:jetty;
     docker push plantuml/plantuml-server:latest;
 
+    docker build -t plantuml/plantuml-server:armv8a -f Dockerfile.armv8a . ;
+    docker push plantuml/plantuml-server:armv8a;
+
     fi