Integration Test for quickstep_cli_shell

[zuyu]

We should have the integration test for quickstep_cli_shell in the CI test pipeline.

[pateljm]

@zuyu: Can you expand on this? Do you mean an end-to-end test? I'm working on one.

[zuyu]

@pateljm I mean, in the Travis CI we need to run quickstep_cli_shell with some queries, and then compare the query results with the expected ones.

For now, we only have quickstep_queryoptimizer_tests_executiongenerator* unit tests regarding this, instead of the CLI binary.

[pateljm]

Good point. I am working on creating a few queries to do just that. Haven't finished it, but will try and do that soon.