Fix jdk8 installation issue on Travis

Author: reftel

.travis.yml

@@ -3,9 +3,10 @@ env:
   - secure: c66yXHpaxdNkvbPfqQRd+831RmBxaSjJd8eFuQJT7CSq616gGNuWaOcs0MXMM3azIiJBoREtv65pHPrVump8iDeBi9l1cRgtBI7Tv1JOWHNg4nJ4uY1QpHi2SwEbwqu2BwcQDvtf87PbFNjjAVabi/1oqBdXIcOxXwtqqhCWdng=
   - secure: BgJb2chM/LsNm1Q6QJBR68XJC1dfxvhr32AagY996wePmo38kvz29vsaMHlGMZtrFaq0yKrbnmRsyPfemtfgGbxtzYY1RiUFEuRCGfVILZowmqPIHXe68st+iOcr9eD1QPv3HLbyOWzuPwSjdhNV7Dpjk8ELuZeL7ZQogPaGEuA=
 language: java
+dist: trusty
 jdk:
 - openjdk7
-- oraclejdk8
+- openjdk8
 after_success:
 - mvn clean cobertura:cobertura coveralls:report
 - echo "<settings><servers><server><id>sonatype-nexus-snapshots</id><username>\${env.REPO_USER}</username><password>\${env.REPO_PASSWORD}</password></server><server><id>sonatype-nexus-staging</id><username>\${env.REPO_USER}</username><password>\${env.REPO_PASSWORD}</password></server></servers></settings>" > ~/settings.xml