Run maven sample project in the Travis build

Author: ashawley

.travis.yml

@@ -1,14 +1,21 @@
 language: scala
 jdk: oraclejdk8
 scala: dummy # using crossScalaVersions over TRAVIS_SCALA_VERSION
-before_script: cd sbt-sample
-script: sbt +update
+script:
+- cd sbt-sample
+- sbt +update
+- cd -
+- cd maven-sample
+- mvn compile
+- mvn package exec:java -Dexec.mainClass=XMLHelloWorld
 
 cache:
 directories:
 - $HOME/.ivy2/cache
 - $HOME/.sbt
+- $HOME/.m2
 
 before_cache:
 - find $HOME/.ivy2/cache -name "ivydata-*.properties" -print -delete
 - find $HOME/.sbt -name "*.lock" -print -delete
+- find $HOME/.m2 -name "*.lastUpdated" -print -delete