Update SDK (v0.5.6)
Update SDK (v0.5.6)

madtreat/wi-find,cemrich/cardboard-java,jqyp324/-test_cardboard,hassank/Wanderer,MaTriXy/cardboard-java,javacasm/cardboard-java,bobbyang1/testytest,ixeetProjects/cardboard-java,ericlzyu/cardboard-java,omarrach/cardboard-java,farinhite451/Cardboard-Java,knockDOUGH/cardboard-java,hassank/Wanderer,AdamRLukaitis/cardboard-java,lukyth/cardboard-java,landsurveyorsunited/cardboard-java,u-engine/cardboard-java,n-eisner/GoogleCardboard,hassank/Wanderer,googlesamples/cardboard-java