[CMake] Revise travis build script following cmake change.
[CMake] Revise travis build script following cmake change.

kgnk/Halide,psuriana/Halide,kgnk/Halide,kgnk/Halide,psuriana/Halide,psuriana/Halide,kgnk/Halide,psuriana/Halide,psuriana/Halide,kgnk/Halide,psuriana/Halide,kgnk/Halide,psuriana/Halide,kgnk/Halide,kgnk/Halide