Use JDK 7 for Java 7 build in Travis with improved build matrix syntax
Use JDK 7 for Java 7 build in Travis with improved build matrix syntax

feynmanliang/oryx,santoshsahoo/oryx,brummell/oryx,oncewang/oryx2,SevenYoung/oryx,jordancheah/oryx,bikash/oryx-1,chen0031/oryx,nvoron23/oryx,oncewang/oryx2,ChuyuHsu/oryx,bikash/oryx-1,srowen/oryx,dsdinter/oryx,dsdinter/oryx,feynmanliang/oryx,nvoron23/oryx,SevenYoung/oryx,SwathiMystery/oryx,santoshsahoo/oryx,chen0031/oryx,srowen/oryx,OryxProject/oryx,jordancheah/oryx,ChuyuHsu/oryx,OryxProject/oryx,SwathiMystery/oryx,brummell/oryx