updating android sdk version on travis build
updating android sdk version on travis build

dgyuri/robospice-minimal,fahmihidayah/robospice,fahmihidayah/robospice,rav3n/robospice,stephanenicolas/robospice,hejunbinlan/robospice,git4slash/robospice,xsobolx/robospice,Proper-Job/robospice,stephanenicolas/robospice,git4slash/robospice,arunlodhi/robospice,hejunbinlan/robospice,jxauchengchao/robospice,JunyiZhou/robospice,arunlodhi/robospice,johnjohndoe/robospice,Proper-Job/robospice,rabyunghwa/robospice,hgl888/robospice,ldw85/robospice,johnjohndoe/robospice,ldw85/robospice,hgl888/robospice,dgyuri/robospice-minimal,xsobolx/robospice,JunyiZhou/robospice,rav3n/robospice,jxauchengchao/robospice,rabyunghwa/robospice