language: java
jdk: oraclejdk8
notifications:
  email: false
before_script:
 - echo $JAVA_OPTS
 - export JAVA_OPTS=-Xmx256m
script: mvn clean verify -B -f pom.xml

language: java
jdk: oraclejdk8
notifications:
  email: false
before_install: 
 - sudo rm /etc/mavenrc
 - export M2_HOME=/usr/local/maven
 - export MAVEN_OPTS="-Dmaven.repo.local=$HOME/.m2/repository -Xms512m -Xmx2048m -XX:PermSize=512m"
before_script:
 - echo $JAVA_OPTS
 - export JAVA_OPTS=-Xmx512m
script: mvn clean verify -B -f pom.xml

Enlarge memory for maven to get build stable.
Enlarge memory for maven to get build stable.