Add travis setting
Allow JDK8 to fail because fail in plugin test builder

Tests in error:
  org.jvnet.hudson.test.JellyTestSuiteBuilder$JellyTestSuite(org.jvnet.hudson.test.junit.FailedTest): -1
  testCliSanity(org.jvnet.hudson.test.PluginAutomaticTestBuilder$CliSanityTest): second instance