force maven to use updated dependencies.

Author: HugoMario

.travis.yml

@@ -5,6 +5,7 @@ jdk:
 
 cache:
   directories:
+  - $HOME/.m2elp
   - $HOME/.ivy2
   - $HOME/.gradle/caches/
   - $HOME/.gradle/wrapper/
@@ -76,7 +77,7 @@ script:
   # fail if generators contain tab '\t'
   - /bin/bash ./bin/utils/detect_tab_in_java_class.sh
   # run integration tests defined in maven pom.xml
-  - mvn clean install -X -e
+  - mvn clean install -U
   - mvn -q --batch-mode verify -Psamples
   # Below has been moved to CircleCI
   # docker: build generator image and push to Docker Hub