Travis: Disable some gcc warnings to avoid exceeding Travis limit
Travis: Disable some gcc warnings to avoid exceeding Travis limit

See: https://github.com/xianyi/OpenBLAS/pull/1255#issuecomment-318628666

kortschak/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,kortschak/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,kortschak/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS