* Add support for async query. Only insert result is parsed.

* Add support for connection pool.

* Add one case for lua connector in smoke test case list.

* Build dymanic library for lua connector before smoke test.

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

modify smoketest.sh to python3.8

* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.

* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.

* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

change focal to bionic.

* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.

cherry pick from master.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

change focal to bionic.

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

install python3.8

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

install python3.8 and pip, setuptools

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

install python3.8, and install pip and setuptools

* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.

modify smoketest.sh to python3.8
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

[TD-868]

[TD-786]

[TD-725]

[TD-351]

[TD-214]

[TD-205]