add unittest (#29)

diff --git a/tests/scripts/task_python_vta_tsim.sh b/tests/scripts/task_python_vta_tsim.sh
index 0251915..ae9bedf 100755
--- a/tests/scripts/task_python_vta_tsim.sh
+++ b/tests/scripts/task_python_vta_tsim.sh
@@ -49,6 +49,7 @@
 
 # Build VTA chisel design and verilator simulator
 echo "Building VTA chisel design..."
+make -C ${VTA_HW_PATH}/hardware/chisel unittest
 make -C ${VTA_HW_PATH}/hardware/chisel cleanall
 make -C ${VTA_HW_PATH}/hardware/chisel USE_THREADS=0 lib