Try Travis OSX builds again
matrix:
include:
+ - os: linux
+ jdk: openjdk7
- os: linux
jdk: oraclejdk8
- os: linux
jdk: oraclejdk9
+ - os: osx
+ osx_image: xcode7.3
+ - os: osx
+ osx_image: xcode8.3
+ - os: osx
+ osx_image: xcode9.2
language: java
script: mvn clean install -Dmaven.javadoc.skip=false
