Sincle we introduce new singlenode deploy mode, we should add related tests in CI/CD pipeline.
I have discussed with @sandiandian , he will take care of it after #77 is merged.

Follow the steps bellow to run singlenode test:

0. build as cbdb's usual way
1. make create-demo-singlenode
2. make -C src/test installcheck-singlenode
3. make destroy-demo-singlenode